F150 Runs Rough, Lean P0171 P0174 (SI Ep 6.2)

This 2005 Ford truck has the classic lean DTCs P0171 and P0174. My first thought was...VACUUM LEAK!
But not so fast...
Enjoy!
Ivan

[@shaneliekhus2129]

Thank you for this. I have now learned this lesson the hard way, just glad I held onto the old breather box. My 2008 F150 5.4l 3v reacted EXACTLY the same as the one in you video.

[@fieldsofomagh]

All those mods are a mechanics nightmare.Great video and job well done.

[@dil6969]

Owner - "The box said 10HP" I would guess with that huge pipe, the velocity of the air entering the engine is greatly reduced, which would change the rate at which the hot-wire is cooled. The sensor requires less current to keep it at a constant temp with reduced air velocity. Yet the actual volume of air being sucked in is considerably more, causing the lean condition. This is something I never actually thought of until I saw this vid. Nice work, Ivan!

[@justusetpecator]

Been working with the same codes. ('02 Expedition 5.4) Just got a scan tool to read fuel trim. Watching you diagnose the 150 was very educational. Mine turned out to be the PCV line. Did not need scanner tool to find that but is was nice to use it to confirm the fix. Thank you for posting.

[@MA-ct7qr]

I appreciate you take the time to explain what you’re troubleshooting and how you perform diagnostic testing. Thank you. MA

[@nickc7494]

Excellent video, helped me with my 5.4 Harley Davidson

[@FordTechMakuloco]

Turbulence of the airflow is part of the problem here we have seen everything from lean codes to a rolling idle to hesitation to P061b code on ETB vehicles all due to swirling of the air past the maf. Sometimes manufacturers like GM use screens to straighten the airflow before the maf to get the most accurate reading possible for the best control of the fuel trims. Great video Ivan!!

[@reweydewy]

FordTechMakuloco Nice to hear it right from the Ford tech

[@PineHollowAutoDiagnostics]

Thanks for the comment, Brian! Does Ford use some sort of air flow straightening device or venturi for proper MAF measurements?

[@FordTechMakuloco]

motoYam82 I have only seen the screens on the Windstar vehicles personally.

[@rrmech11]

FordTechMakuloco very true

[@alb12345672]

Great info! Also, correct me if I'm wrong, but I don't think newer Fords don't compute baro from the MAF sensor, they do it some other way. I've seen the code from the older PCMs and BARO is computed with a complex equation involving MAF airflow. Older fords would give a skewed baro and you would have known right away there is a MAF issue, either dirty or just not right. Baro used to be a very powerful diagnostic tool, now not so much.

[@clydehanamaikai1394]

Had a check engine light on my 95 ford windstar & it was running lean. Forgot what code it was. Long term fuel trim was high. It was a dirty MAF sensor. Clean the sensor & it fixed the problem. Great video. Thank you.

[@CopCat34]

Great detailed diagnostic video!

[@4WDIESEL1]

great video. please keep them coming as this better than top gear

[@RobertL78]

This video helped my solve my lean codes on my Ranger. was reading +24% and +17% on LTFT's on bank one and two. Swapped out an aftermarket MAF to the OEM one and put in new O2 sensors, now I have 0% and -4% LTFT's. As soon as I unplugged the aftermarket MAF, it died, then I restarted it with the MAF unplugged and the fuel trims dropped like a rock. OEM worked perfectly. Although, on my scanner, the two MAF had nearly identical volts and g/s of air showing at idle...... Thanks!!!!

[@chanceberg832]

Thank You I spent a Lot of Money Trying to Figure This out ...My Friend Told me What To Look For But I'm Not As Good As You And Him ...I am a Man Though trying To Survive in This Economy 🙏🙏🙏 Supporting a Family By Himself..Thank You Very Much For helping The People Who Don't have it Made..This is by the Fire Wall off The intake PVC Plastic BS...This my 1st Ford 2002 F150 Triton

[@DEBOSSGARAGE]

We had a lean bank of a 5.4 Triton. All it ended up being was spark plugs (everything was still stock). Great video, thanks!

[@rusco321]

DEBOSS GARAGE Motorcraft spark plugs?

[@joemilton7552]

How did the spark plugs throw a lean code?

[@fireboy5043]

​@@joemilton7552😂 ???

[@MichaelMcNeilg]

Kendra and Natalie lmfao Eric O cracks me up great videos Ivan

[@HUBBABUBBADOOPYDOOP]

*STUPID IS AS STUPID DOES. ALL THAT FAST AND FURIOUS CRAP.*

[@SmittySmithsonite]

That was an interesting one Ivan! I'd have been scratching my head over that one for a bit.

[@mnrujiska771]

Sretan Bozic C рождеством!

[@kyhomegarage3430]

Awesome work,keep up. Cheers

[@michaelkane732]

GREAT VIDEO!!

[@whitetiger8652]

Nice job Ivan.

[@cobraninetysix3883]

Great video!

[@wmichaels362]

Good video, and great detective work! At GM's Intake Product Development Team meetings, there was (I'm retired now) a LOT of discussion around aftermarket 'performance' intake systems/air filters/boxes. The diagnostic calibration engineers (they set the pass/fail thresholds for components & systems) had many examples of non-OEM performance parts failing the diagnostics and setting DTCs. I recall that over oiling the K&N filters contaminated the MAF sensors, setting DTCs. Hundreds and thousands of hours are spent dialing in the pass/fail thresholds. It is correct that placement of intake system components can be a factor. The same engine in a different platform/body style can often need a specific diagnostic calibration as well as other engine management calibrations.

[@PineHollowAutoDiagnostics]

Great comment! Yes the engineers do a lot of work and then consumers just rip out the stock system and slap on a shiny tube and expect it to work fine lol

[@thomaspapa3831]

I'm learning every day watching a pro !

[@joe2mercs]

great video Ivan, at the start you asked why the short term fuel trims were not maxed out (0.8%) while the long term fuel trims already were (29.7%) for both banks. Short term fuel trim changes accommodate an immediate condition such as a vacuum line suddenly coming adrift or even when the car is cold and it needs more gas just to warming up; don't look at short term fuel trims until the engine is in closed cycle. If the hose remains disconnected the long term fuel trims will be set to live with this condition. With the long term fuel trims accommodating a long term change the short term fuel trims, having done their job, return to zero. I know you love to do the numbers, looking at the air flow rate g/second value shown in the PIDs you can work out, based on the revs per minute/60 and engine displacement, whether the amount of air that is entering the engine matches the value as calculated by PCM. The disconnect between the values points to air volume sensor error. Is it possible in the computer to simply plot the air consumption of the vehicle based on revs and engine size versus the g/sec as seen by the PCM? As this would highlight the problem immediately.

[@parallelpost]

Thanks, nice post.

[@willemstreutgers1154]

Nice diagnose Ivan, upcoming problems with thosse K&N oiled filters is that they ruin the MAF because the oilmist sucked in is burning on the heated resistors in the MAF. So stay with the OEM filters is an good advise.

[@michaelovitch]

You need a laminar airflow for MAF sensors. The problem here was the ugly elbow just after the air filter. You would install a straight tube with the filter at its extremity and it would work well. Even straight pipes with no filters can be a problem. The pipe's ridge create an airlift and messes up the airflow. A simple vacuum hose sliced on its length and covering the ridge is often enough to make the airflow laminar again.

[@baxrok2.]

Nice fix Ivan. Confused me a bit since the complaint was that it ran crappy only intermittently. MAF was definitely low for that 5.4. The SIE is the gift that keeps on giving. Thanks for sharing this there were some good lessons!

[@PineHollowAutoDiagnostics]

Thanks John! I think the crappy running was mainly due to that failing ignition coil, a separate problem from the MAF issue we saw here.

[@pneumatic00]

I had a Ford Explorer Sport, 4 liter engine, 44K mi, I think it was a 2003, that threw those exact two codes. Thought it was the MAF but replacement did nothing. Turned out there was a fairly short length of 3/4" hose (foot or so long) pretty much right on top of the engine (I wish I could tell you what where) but it had a BB-sized hole in it, on the underside where you could not see it. The hose looked just fine, not cracked nor dried out, it didn't look like it was running over anything mechanical that would wear a hole in it, you'd probably not suspect it. Took it off and there was a stupid obvious puncture in the hose. Well, it wasn't "obvious" because you could not see it until the hose was taken off, but with the hose just sitting in your hand, there it was.

[@markferraro5250]

ivan would you consider that an intake restriction? would baro or map from a scope show anything with any diagnostic value ? great video those aftermarket cold air intake drive me nuts also

[@somerandomguy3868]

thanks I wondered about aftermarket intake glad I never got one

[@mhn3773]

I will bet the owner continues to try to "have this fixed" once you tell him all the blue/silver crap is the issue. Thanks for the video.

[@EagleAutoshop]

Great info Thx we have one we are fighting with right now and I am going after MAF.

[@paulnewkirk7351]

My wife ordered a 2005 gt mustang. Once delivered, she wanted a hood scoop. I went all the way and put a shaker with K&N filter. The computer gave indication there was a problem but after 25 miles all was good. Never had an issue getting inspection and owned the car until 2020.

[@retroguitarmaster]

dude you don't understand, if you buy enough cheap shiny ebay parts, vin diesel comes to your doorstep and pads you in the back

[@PineHollowAutoDiagnostics]

LMAO

[@randytheapplianceguy8838]

this was great.

[@Tedybear315]

Gotta love that Hot Air Intake!! ghess... People, Leave the stock air box alone. Just get a high flow air filter (or just make sure your air filter gets changed out when it gets dirty.) *edit* I thought the bonus footage would have been some teenager coming out and yelling about how his buddies and the parts store people told him he could gain 1.21gigawatts of pure power with that setup.. And now back to your normal viewing....

[@Duke_of_Prunes]

The stock box on the F150 is great. It is the restrictive short piece of tube going into the fender that stinks -- swap that out with scrap pvc and you're all set.

[@webslinger2011]

Did the rpm feel slow going down when you decelerate? Slight hesitation at around 1500-2k rpm. But not enough to cause a code. Had a complaint on a 2005 holden barina. Engine shakes in the morning. Once it's hot it goes away. Found intake wasn't put in properly. Air was seeping in before the MAF.

[@iduimovic]

I love Ivan's videos. To clarify something here. That is not K&N filter or intake. That is a cheap aftermarket eBay imitation that has been fitted on that truck. The filter is a cheap aftermarket replacement that is not doing the job (well actually it does, it is restricting more air that it should) plus the OEM box was cut to hold the hanging pipe and the pipe has a sticker on it that says AEM that probably someone stick on the pipe to make it look expensive. (AEM has factory brackets that will fit on the vehicle with no modifications. Base on the pimp my ride truck that we all saw with color aluminium foils on hoses, unplug cables, half aftermarket pedals and who knows what else, that is the result of not knowing what are you doing. Not all aftermarket are bad, jut look for the one specifically design and tested for your vehicle, not just something that with some modification may be required will work on your vehicle. Nice job finding out the problem Ivan.

[@PineHollowAutoDiagnostics]

But at least the blue color looks cool and actually cools the incoming air charge hahaha

[@Mikeywil0003]

Im sure those foil heater and radiator hose covers add so many horsepowers.

[@PineHollowAutoDiagnostics]

Should have taken that beast for a test drive...

[@figibloom]

Hey great video and great diag. One thing I noticed right away was the baro sensor was not quite reporting quite correctly. I know on many systems the baro gets its info from the MAF and originally I saw it reporting between 28-29 which is between 2000-1000 ft above sea level (i think it was at 28.9) Well according to a Baro chart I saw for F150s (inhg (kpa), baro hz, altitude) 28 94.6 152.8 2,000 29 97.9 155.8 1,000 30 101.3 158.9 0 (sea level) I believe the baro frequency was in spec but the baro inhg was off a little bit, and in your video after pulling that after market crap off I noticed the fuel trims corrected, but also the Baro shot up to 30.1 you can see that at around (17.06 on your video) which was what is should be at sea level. That is just one more thing to check and look at closely when you think the MAF is out of whack a little, at least that is one thing that has helped me trouble shoot MAF sensors. Well thanks again for the great video I enjoyed watching it. I hate aftermarket add on crap, I just dont get why people want to add stuff like that. Oh well more money for you I guess, lol.

[@PineHollowAutoDiagnostics]

Sharp eye! That's a great observation...the Baro should have been closer to 30inHg at sea level.

[@JOHNPHUFNAGEL]

I haven't finished watching your video but I read that even changing the location from stock position of the maf sensor will have an effect on its reading

[@KNfilters]

Looks like this intake is using a filter that is not designed by K&N or AEM and that will cause a check engine light. More info on product testing is available on our website.

[@wyattoneable]

My goodness. It's to the point you can't modify anything on the newer vehicles. Nice work on your part Ivan.

[@gmoney9588]

Happy new year Ivan ! In the end , it seems that flashy cold air induction , by whatever name , seems to be one big restriction . Don't know a lot about volumetric efficiency versus fuel map but I would say you proved that the restriction is what caused the unbalance of a proper fuel/air ratio which totally disagreed with the engine management system . The engine and its fuel system is totally stock . It can only run on stock intake volume . This is the equivalent of when guys used to take Holley 750 CFM double pumpers and throw them on stock small blocks and expect HUGE power gains . More air into an engine with a stock cam and stock chamber volume does NOT make for efficiency . In this case , it's the opposite . LESS air was being introduced into the engine than stock specs , due to the non-stock intake restrictive filter . It would not even idle right . The fuel system via the O2 sensor readings were what was compensating for the restriction by opening the idle air control to offset the missing volume . The scan readings showed the fuel trim way off the scale from the programmed fuel map due to insufficient air intake . If the idle air wasn't necessarily over active to maintain and compensate for the restriction , then that would be the manufacturers reason for the huge intake tubes into the throttle body . Looks Badass and makes up for the filter restriction . How could big tubes on a non-turbo engine be expected to flow more air than stock through a stock plenum and lower intake on a stock engine with stock cam ? Bottom line : that aftermarket cold air induction is NOT meant for a stock engine ! It may do well on a turbo charged build but all it's doing is lining the pockets of the store owner from where it was purchased . Ivan just proved that . Don't fall for it . I'm sure ford engineered the intake induction right to achieve correct volumetric efficiency or an F150 wouldn't get out of its own way . Nice job Ivan ! Your relentless efforts to find the faults and install the fix pays off yet again ! If it weren't for guys like you and the shop owner , no one would put in the time needed . The video was only 18 minutes long , that's less than an hours labor charge . Ivan just saved huge $$ dollars on dynometer sessions and guesstimates . This is why Ivan gets the job , get 'er done and save $$.

[@davidberry1379]

I've been running a K&N filter system on my F-150 for nearly 15 years, self installed, without issue. 5.4L has 200,000 miles on it, and anytime I've gotten these codes it has been a vacuum leak. Once the PCV octopus was basically falling apart, replaced it with no issues. My K&N has a straight run past both sensors before it curves into the throttle body. I have never cleaned the MAF routinely. but i have cleaned and oiled my K&N filter regularly. I also paid north of $300 for this cold air system so I didn't go cheap on it. Obviously, it was well designed and the truck had no issues with it (still does not!)

[@darrenairey5938]

Same here! No issues with my k&n fipk maf reads 5.6g/s at idle. 10 and 11 gen f150s are notorious for vacuum leaks tho! Specially the main vacuum on the backside of the throttle body plenom close to firewall.

[@johnmckamy6398]

nice catch

[@THEGAME-tz6yu]

Great info

[@agoodneighborautorepair2176]

Hi sir,very interested case,The picktail that you find lost in the Passanger side it's probably for the PCV valve on the cover?!..thank you.

[@sewerratt47]

EXCELLENT

[@dukeman7595]

I think the intake has a hige vaccum leak. These engines are notorious for this problem, I realize the aftermarket crap has a lot to do with it, however, most of these leak from the intake.

[@joeshearer1247]

As a HVAC technician I could see how the air flow through the bend in the pipe would be hugging the outside radius and the MAF was on the inside radius side

[@josholson5015]

Joe Shearer I didn't notice that but it makes sense. Most MAFs I have seen come with what looks like a honeycomb grid to help organize the air columns. The aftermarket junk also deletes the reservoir box that holds air. My understanding is that it is there for rapid throttle openings that deplete air behind the filter. Loss of air when you really want it?

[@terrencedillon4345]

I would spend it. Unless you don’t have it. No insult intended. Good video.

[@riblets1968]

I was very surprised by the fix! How does that affect airflow metering?

[@johnyoung4467]

do you think it was the way the air passed over the MAF, or was the air filter a restriction?

[@billyhillbilly1356]

"?" "DAMDIT" ELECTRONICS < ! OLD SCHOOL!

[@bigdaddymak1439]

These intake have been proven over and over to be absolute garbage stop putting them on your vehicle!! Great video Ivan!!

[@davidhampton8517]

What is this tool your using to read this stuff? Is this an app i can get?

[@Jerone5740]

yaay!! I'm NOT going to get K&N cold air filter for my 13' Taurus

[@69jagss69]

Had the same problem. It was the vacume. Their is a 3 port connector behind the right lower intake ..have yo remove fuel rails and upper then barely squeezing your hand back there

[@rhkips]

It's not a Kendra & Natalie; it's an Allen Ernie and Martha. ;) Good find! I'm willing to bet if you rotated the MAF housing 180 degrees, it'd get the signal back in range. That elbow in the pipe is a bit too close to the MAF; all the air is still hanging out against the far wall of the tube away from the sensor. Rotate the sensor into the airstream, and you should be able to get the truck back on the road, should the customer decide to keep the aftermarket intake. :]

[@kdmq]

When you snap throttle to check the MAF, remove all the other PiDs so that the aliasing isn't as bad.

[@adamlenning6076]

Them newer Fords have to be tuned when you install a air intake on them for them to run right.

[@johnmckamy6398]

I think the sensor looks for a particular air speed or pressure , that aftermarket tube is probably bigger ect.

[@billarruda2777]

He sees that Ivan always takes the long way around try to diagnose the car one time without the scanner, That’s the way we used to do it back in the old days. In actuality to Scana can have your chasing your tail

[@ryanmalone844]

I had a PO174 on a 2003 f150 and there was a slight exhaust leak where it connects to the manifold. I just had to replace the 2 nuts that were rusted. There was rattle for several months before it finally threw the code.

[@davidmartin2231]

Some cold air kits come with an insert around the MAF to run without a tune. Obviously this might’ve been the case and of course that brand is usually what autozone or o’reilly’s sells lol

[@adamtrombino106]

Fords are very intolerant of variations of intake air flow when using MAF. Even cheap aftermarket filters in an OE application can change the flow rate and cause codes. A couple of 10ths of a volt means a great deal. If you're going to run 1 of these cold air intakes, etc, you need to have the ECM tuned for it.

[@franciscovasquez7541]

What's the model number of the snap on diagnostics tool you're using?

[@tunercars3]

thats not the problem what it needs is a tune for the the aftermarket cold air intake what most people fail to realize you can't just add Parts without tuning or the stock computer doesn't know what to do so it either overcompensates or under compensate same thing with adding high octane fuel if the timing isn't set up for it you will actually lose power it's all in tuning the aftermarket isn't garbage the tune for the truck is garbage

[@haywardsautomotive6156]

Ivan great video but I have a few questions you may have the answer to. How long has that cold air intake been on the truck b/c that is an AEM kit but appears to be a Spectre or another manufacturers air filter b/c it is blue & AEM are red and it looks fairly new. The reason I ask is b/c if it is a dry filter & someone oils it then it will do that and actually chokes the filter. Did anyone try connecting the tube and just removing the air filter? What did the owner do to fix it...maybe Keith knows. Just curious b/c it's bugging the crap out of me b/c normally AEM intakes don't lower the MAF reading like that it actually goes up slightly. I noticed when you started it and the rpm stabilized the MAF was showing 5.31 g/s at 672 rpm and then dropped to 3.88 at 652 rpm...wonder what throttle angle was at. Anyways great video and diagnosis as usual!!

[@PineHollowAutoDiagnostics]

Keith will be doing the final checkup on this vehicle next week. I believe the stock system was reinstalled by the shop...

[@haywardsautomotive6156]

motoYam82 OK thanks

[@RussellBooth1977]

It sounds like the K & N air filter was restrictive rather than higher flowing than the stock air filter !

[@Duke_of_Prunes]

Spray enough of that goofy oil on there and it's like flowing air through a wet sponge.

[@hxc7273]

Opening the hood and seeing that crap would've made me want to walk away. Next thing the customer will say is that it ran fine for years with that setup.

[@ericlacombe4124]

And if it did?

[@rcworks9762]

I didn't see the aftermarket cold air BS... yeah the curse of the modern tech... I had a Mazda Miata come in with one... I was able to retain the cold air, the problem was the sensor was was measuring the flow while turned backwards. I've seen just about every lean condition a Ford can make. Most of the time it's dried out rubber gaskets or the PCV harness

[@frankgonzalez24]

I have a K&N cai on my 07 2.4L Cobalt SS. I took a screen shot of my idle maf readings before installing and after. Reading were the same. The cai has been on for several months and the C/E has never never turned on. And yes, the bulb turns on with the KOEO.

[@thetinpin]

Cool story bro

[@satamanschmidt3428]

Ivan, I know you idolize ScannerDanner but with the beard you're actually beginning to look like him.

[@waderigsbee6923]

looks like eric o too.

[@baxrok2.]

Hmm, good point. I'm gonna grow a beard too if it means that some of their skills will rub off on me!!

[@PineHollowAutoDiagnostics]

Yeah had to join the bearded diag club...the experts say it can cut diag times by up to 50%!

[@movingupautodiagnostics8645]

Now we're separating boys from men.

[@jamestate9753]

Had the same error codes on my 01 Expedition, replaced PCV valve (never changed), replaced fuel filter and cleaned MAF sensor...just basic items. Turned out it was the fuel pump.

[@rbbbjl1]

That was a real eye opener about trying to improve on engineers design, forget it, all its going do for you is cost you money and screw up your cars performance to boot. Nice job ivan the terrible

[@tinkerwest]

probably needed a good cleaning or replacement if problem occurred after quite some time running ok with k+n filter when first installed...most people never clean them or do an adequate job of cleaning them...i still dislike them regardless...as ivan says, engine was designed to operate certain way and people go and install these filters and it can change operating parameters...

[@johnmckamy6398]

nice

[@gurlno9007]

Did anyone ever check the VCT solenoids/valves? They are notorious for going bad on this make/model/year and causing your PCM to throw crazy codes like this. Make sure the right oil is in this truck as well. Ford calls for W20 but W30 can be used as well. The triton engines especially heritage 04s and newer O5 have all these little screens and parts that dont get properly lubed with the thicker oil like the VCTs. So while your shop is looking for the ghost rattling its chains in your engine, the real culprits, VCTs, arent being looked at bevause there is no code that simply says VCT SOLENOID

[@jamespizzi6689]

I feel your pain. I work at a shop that sells those air intakes and a lot of times I have have to re-engineer them so the vehicle will run correctly and not have a check engine light on

[@jeremiahlinton9582]

How did you fix them

[@cantorianovm91]

My tsx got 2 codes p0171 and p0134 dose that mean i just need to replace the o2 sensor?

[@bettertruththanlie1075]

Hi. In which state are you working?I need to fix 3 cars-mercedes ml 430,chevy silverado 5.7and subaru impreza they 1998,2000 and year 2006-all in north Seattle

[@PineHollowAutoDiagnostics]

I'm in Central PA...sounds like fun projects!

[@JOHNPHUFNAGEL]

Not sure why they call that a cold air intake when its actually sucking hot air in from under the hood. The factory setup is actually a cold air intake because most have ducting that pulls air in from the grill area or the bottom of rad support

[@PineHollowAutoDiagnostics]

You got me there I've asked that question for a long time too...

[@JOHNPHUFNAGEL]

are you going to vision2017 with Paul for training?

[@Nick-dw3sv]

sounds like the chain tenchingers are going out or are out....

[@teamkanaway]

Hello how are you how to get copy the automotive scan Diagnose , I'm doing also a Diagnose but base on my manual experience

[@ElverGalarga-lj9ss]

So what fixed it? I have exactly the same problem on mine with an oem air cleaner

[@Travisfromoregon]

Ivan, do you have a video of all your diagnostic tools? Wondering if you've ever used the escope by bernie tompson.

[@PineHollowAutoDiagnostics]

I have not personally used one, but I know Bernie is an automotive genius, so it's worth a look! I don't have a tool-specific video, but could put one together if you're interested :)

[@Travisfromoregon]

I would be interested in how you acquired your diagnostic tools, and started out. I've be looking into getting a pico for diesel diagnostics. Looking at bernie's scope 8channel and with everything his stacked it with. Hard decisions, what his done with simple obd2 blew my mind. lol

[@mohammadaburabee4980]

Hi My car doesnt have maf sensor, i get high 20% ltft What would be the problem?

[@billgator2005]

appreciate the diagnosis but seems only a too restrictive air filter.

[@turnupdot2108]

hi can someone please leave a link for a mass air flow sensor and the pcv valve and hose for a 98 f150 4.6???

[@ellobo8593]

Damn you AEM, to bad there the best on the market.

[@anthonymazziotti1605]

i have a ram air sys in a custom made hood on my f150 5.4 3 v . when I- drive the truck i get a lean code in both banks

[@hddm3]

Hahahahaha wow just wow. All i can say but you know what im thinking

[@theoldwizard998]

Interesting that the air flow through the after market tube (which is nice and straight) would cause such a problem. One think about those K&N filter that most people don't know (Because they don't read the directions) is that they actually require servicing much more often than a paper filter. They do work well when properly cleaned and re-oiled when necessary.

[@ale6242]

no they do not... they need cleaning when they get reaaalllyy dirty, but that wont happen for well over 2-3 years in the dirtiest of places. www.knfilters.com/cleaning-pics.htm that's one of the major selling points.buy it, and you dont have to buy another one ever again! just clean it after a few years.

[@PineHollowAutoDiagnostics]

The problem isn't so much the filter, but the location of the MAF and the way the airflow passes over the hot wire. Stock system are engineered very specifically and the fuel maps in the PCM are programmed accordingly. In this case changing the geometry and relocating the MAF skewed the airflow readings quite a bit!

[@haywardsautomotive6156]

K&N recommends cleaning every 50K miles

[@ale6242]

exactly!

[@Sncedayone]

Nice hot air box intake

[@TopZ92]

I have even seen on a turn where the engine would run rich because the fuel pressure regulator got its vacuum from the intake tube and with the k&n would so well it wouldn't create a vacuum

[@PineHollowAutoDiagnostics]

Interesting...usually there is negligible vacuum in the intake tube before the throttle plate...unless you airfilter looks like a mouse nest lol

[@TopZ92]

Yes the factory system had a small type canister type champer on it to store vacuum for the fuel pressure if I remember correctly it was something like a 03 tundra with a 4.7 really weird

[@ozzstars_cars]

Aftermarket dooky

[@markrup6369]

So, help me understand the issue here, Ivan. If the CAI was "choking" off the intake and the MAF was measuring correctly, shouldn't the fuel trims be negative? If there's not enough air going in to keep the A/F ratio at 14.7:1, then the computer should be taking fuel away, not adding fuel -- as we see here. Please explain. Thanks.

[@PineHollowAutoDiagnostics]

Not quite. The aftermarket CAI was "disturbing" the original air flow stream as the engineers designed it. Therefore the MAF was not reading the air flow correctly (too little), and the computer had to add fuel to compensate for this error :)

[@markrup6369]

Ahh... makes sense. Thanks Ivan. I'm an electrical engineer with 30+ years experience and yet you have taught me a lot. I really appreciate your channel!!