2 Ways Test a MAF Sensor with a Low-Cost Scan Tool (Mass Air Flow Sensor)

How to test a MAF (Mass Airflow Sensor) with a low cost OBDII scan tool.
Amazon Link LAUNCH CR319 Scan Tool: amzn.to/3JyyWEY
Read here for more MAF sensor testing information.
www.backyardme...
Test #1
Go to Live Data or Data Stream depending on the scan tool.
Find the MAF Sensor data Grams per a second.
Examine the Grams per a second.
the number should not be crazy high with the engine off and not running.
Test #2
Go to Live Data or Data Stream depending on the scan tool
Find the MAF Sensor data Grams per a second.
Start the engine and examine the Grams per a second.
double the engine RPM.
The MAF sensor Grams per a second should also double.
www.backyardmechanic.org
By using this information user assumes all risk of use.

[@mogumatrix]

I'm sitting here with my OBD on my lap hooked up after replacing my MAF and this was the video I needed to explain the graph, Thanks.

[@falcorthewonderdog2758]

MAF sensor data is dependent on an engine with no intake vacuum leaks and no exhaust leaks. Assuming the engine integrity is good the MAF sensor should read grams per second close to 1 gram per second for each liter of engine displacement. An 8.1 liter V8 should read a minimum of 8.1 grams per second at idle. Second example a 3.4 v6 should read a minimum of 3.4 grams per second at idle. A 2.0 liter 4 cylinder should be close to 2.0 grams per second at idle. If the reading is low check for dirty MAF sensor, vacuum leaks lose clamps or attaching hardware on the intake tubing, clean air filter etc, and lastly exhaust leaks causing poor oxygen sensor data. If everything checks out and cleaning the MAF sensor doesn't correct the issue replace the MAF sensor. Retest and verify the correct data of 1 gram per second at idle for each liter of engine displacement

[@SystemForSuccess]

Mine is 9g and it’s a 2.0l 4 cylinder

[@jeeperjeeper2956]

​@@SystemForSuccessTurbo?

[@SystemForSuccess]

@@jeeperjeeper2956 yes a Turbo Diesel

[@MrCeora]

Damn. I wish that I had saw this before I went to the mechanic. I needed to know how to read this tool. Thanks for posting.

[@limeallens6160]

every engine will be different so knowing what engine your testing helps

[@falcorthewonderdog2758]

In reality MAF sensor works pretty much the same on all engines. A good MAF sensor will report approx 1 gram per second airflow for each liter of engine displacement. Example a 6.0 liter V8 will read over 6.0 grams per second at idle. A 3.0 v6 will read over 3.0 grams per second at idle. Lower reading indicate a possible dirty MAF sensor wire causing a low reading or possibly intake vacuum leaks or exhaust leaks ahead of the front oxygen sensors. This test will allow you to track down and eliminate these leaks. After verifying the engine doesn't have these issues if the reading is still below 1 gram per second airflow for each liter of engine size then replace the MAF sensor and retest. Exhaust leaks have been an issue people don't consider and I've repaired these issues to correct others misdiagnosis of a "bad MAF sensor" Hope this helps.

[@Fayis1341]

@@falcorthewonderdog2758🔥💯

[@angeloya2832]

Thank you for the video and those that gave other details!

[@dtamburri]

Great process!

[@tele1311]

Great video thank you for the info. 2008 Chevy suburban would not accelerate smoothly from 1500 to 3000 RPM.. after 3000 RPM, the engine would surge with power. No engine codes present. Just by chance I had the original sensor replaced it after about a week of driving it must’ve recalibrated acceleration is back to where should be..

[@JoseFernandez-zt5xs]

Right on the point thanks

[@dekalogue]

Thank you for making this video.

[@ajayb2478]

Thank you great video

[@fugazi225]

Thanks for info

[@jacobk1160]

You’re videos kick ass dude. Thank you

[@TheNightmare692009]

My PMAS HPX-E slot style mass air is reading .6gr key on engine OFF. A bad maf would explain my issue. Thoughts?

[@charleswilson3493]

Great video thanks!

[@idriveanything1701]

Don't forget for correct readings engine must be up to operating temperature with no load to get proper reading. My vehicle for example says 2.0-6.0 gs at idle when warm which mine is 4.6 so it's fine on a cold start its 18-20gs until warm and this is mid winter in Canada. Before starting vehicle mine showed 1.8gs with key on. Also my vehicle specs show 7.0gs -20gs at 2500rpm mine goes to 15-16 gs 2011 pathfinder 4.0 Yet im still getting a p0101 code i changed maf to a new one erased code it came back put original one in came back so im stumped atm i did change my intake tubes as they were dry rotted and cracked also. Vehicle runs fine dosent miss or anything and drive ability is great

[@KingBigBabyJesus]

Did you figure it out? You should check the wiring if you've ruled out the sensor.

[@idriveanything1701]

@KingBigBabyJesus no I found online nissan had a service bulletin for this code and only way to get rid of it is take to nissan and have them charge 2 hrs to clear the ecu

[@EliteTurtle05]

thanks heaps for this video, my 2.5litre turbo diesel has been idling rough and I figured it idles from 14g/s to 20g/s (fluxulates between those 2 values every second or so), and my sensor reads 1.53g/s when the car is off. I have ordered a new sensor online, hopefully all goes well.

[@rigorsaif8973]

Did changing it fixed the issue?

[@briansantos2206]

Here for answer as well

[@Marinalin85]

​@@briansantos2206so am I 😅

[@Eng_RAY]

What happened to you?

[@EliteTurtle05]

@@Eng_RAY ended up being a suction control valve, not the maf sensor

[@aldrickmoore6908]

GM, my 98 s10 4.3l engine light came on once I unplugged the sensor after the maf sensor, the truck was running and I just unplugged both sensors one at a time, after I plugged the last sensor back in the vehicle started idling a little high, and that's when the engine light came on, I don't know the name of that sensor is called

[@djcutz]

Great Info thanks for this video!!!!!!

[@ahmedbelazi2318]

I measured my car, a 2007 Kia Optima, with a 2.0 engine... at idle, it was 2.3 g/s... and when I had double the pressure, it was 4-5 g/s.. Does this mean it is good??? Because when I removed it while the car was running, the car did not turn off and continued to run

[@ericj6559]

I tested my car with a Blue Driver and it read around 1.5 grams per second for a 2 litre engine. I removed and cleaned the sensor (MAF sensor cleaner), and the reading went to around 2.1 grams per second, right around the 1 gram per litre of engine displacement range.

[@Evan_Floyd]

Thank you Matt Walsh

[@Eng_RAY]

Is there a difference between gasoline and diesel engines? Because I have a diesel engine and the reading in operating mode is 10-12 grams. Is this normal?

[@JonxPon400]

Ty

[@shaijugm]

My maf sensor 40 g/ second in 2000 rpm, it is normal

[@dtamburri]

What does it mean if the value at 2x RPMs is 30-40% too low

[@MrSamiAlamir]

Hi bro i really need your answer my IAT sensor tells me that the Air intake temperature is after i run the car for over 10 minutes 70° to 86°C but the weather temperature is 29°C and at night. Is it normal to get that hot?!

[@HVAC_Mechanic]

If the IAT sensor is reporting a different temperature than what the air is, then it is likely bad, or the wiring going to the sensor is open/short. When they go bad, they often report high or low temperatures.

[@MrSamiAlamir]

@@HVAC_Mechanic Thank you so much for your reply, I will check the wiring if not from them i will replace it because the check engine light is off i was wondering if there is a problem but the ECM doesn’t recognize it and thinks that the weather is hot and dealing with the issue as if it’s hot 😅.

[@gustavomartinez324]

That’s great advice what engine size on the this particular car u have hooked up to

[@HVAC_Mechanic]

This was a Toyota 1.8 Liter. I should have mentioned that an engine uses 1-1.2 Grams Per Second of air flow for every liter of engine size.

[@gustavomartinez324]

@@HVAC_Mechanic yes sir needs minimum air flow to overcome the parasite loss of the motor

[@gustavomartinez324]

@@HVAC_Mechanic yea Kia and Hyundai use little more airflow at idle but you are more of a expert then me by the way great rule of 👍 thumb

[@davis1984100]

Hi thanks for the video. I got a cuestion,,I hot a nbs 07 silverado I used a scanner and all the time it's reading 0.01 0.05 all the time,it doesn't reach at least 1.0 or something like that, always stays under 0.05 or so,will be a bad maf or is it normal,the same happens at idle no rech higer number like your video

[@HVAC_Mechanic]

In general, at idle, an engine uses 1-1.2 Grams Per Second of air flow for every liter of engine size. So, a 5.3L engine should show around 5-6 Grams Per Second at idle.

[@sleal1194]

I know this is a year old but if your still making videos could you maybe run though live data and kinda explain what the readings are and about where those readings should be at normal. Thanks

[@gustavomartinez324]

Look if u have 1.8 L engine u should be having 0.18 to 0.20 grams per second of airflow at idle that would be normal that is needed to overcome the parasite loss of the motor but at wide open throttle u would need alot more airflow since the ECM is multiply base air equation to knoe how much fuel to inject and injector on time in milliseconds but yeah if u have any questions feel free to ask

[@rapss4942]

hey i have the same scanner and on datastream there is no MAF even tho i scroll down i cannot find it

[@eddiec3961]

Hi thank you for posting very good video. What if I have a 0.0 at idle?

[@HVAC_Mechanic]

A MAF sensor should range around 2-7 grams/second (g/s) at idle depending on the engine.

[@menombakglobalis]

1-1.5v at idle

[@MechanicBundy]

What should it read at key on engine off opel insignia mine read 0 is that normal?

[@lgbt_is_nono3867]

At 0.21 and changed the pigtail, checked volts on each prong, new max sensor, but it stays at 0.21 unplugged and plugged in, and started

[@macknumber9]

Are you a hvac mechanic or auto mechanic?

[@starhawke380]

So if I have a P0102 code registering low voltage for MAF, and this test shows the sensor is good, where am I?

[@HVAC_Mechanic]

I would fix the low voltage problem. This is a rough test to see how the MAF sensor is working. The issue may also be intermittent with the sensor working good sometimes and not other times.

[@starhawke380]

@@HVAC_Mechanic that's a relief... intermittent problems are the easiest to fix, right? ;)

[@aliyooo12]

I changed 2 mass air sensor and both of them give me 0.0g/s the wire is good and the air mass fuse also is good any help please ?

[@HVAC_Mechanic]

If the sensor and fuse is good it likely is in the wiring.

[@kicknsystm]

I have a Nissan Xterra, it took a couple times for me to realize it would only cooperate with a genuine Nissan sensor. I got the original part# from the dealer parts dept. & searched online for the best price from there. Some brands only like their own parts.

[@aliyooo12]

Thanks guys the problem was solved i got a original MAF and i dont have in problem now

[@cornelioknelsen5987]

What about when it’s showing 180 g/s at idle and 500+ under load?

[@engmomen9929]

How much IAT should be

[@harisdiz.5817]

do vehicles with MAF have IAT?

[@mannys9130]

Usually yes

[@1983bigfrank]

So my mass sensor is reading 0 when the car is off but when the car is in idle or wrapped up in his reading anywhere from 0.245 to 0.84 grams per min so that does mean is bad and not reading high enough right lately I've been having ass admission cold give me with the mass flow air sensor but about a aftermarket one and it did not work any better

[@menombakglobalis]

depend on the engine size & throttle body size...

[@MechanicBundy]

Did you figure?

[@earthisfat6184]

So mine at maf is greyed out with ignition on and other sensors showing values. Showing no data. Is that a faulty sensor?

[@mannys9130]

Do you have a MAP sensor instead of a MAF sensor?

[@earthisfat6184]

@@mannys9130 no. I've got that car all figured out now tho. Fixed some bad wiring and rebuilt about 60% of the car. Been driving the hell out of it for 3 months now.

[@earthisfat6184]

@@mannys9130 oh and after I fixed some other wiring the maf isn't greyed out anymore

[@eltigre7001]

At idle 750-800 rpm i’ve got 3.7-4 g/s when i double the rpm i get 5-6 g/s is this ok? I cleaned the maf

[@userporpdasd]

U should be getting more

[@pingpong9656]

Will mass air flow sensor behave the same way?

[@HVAC_Mechanic]

A MAF sensor is a Mass Airflow Sensor

[@1hunda100]

👏🏾👏🏾👏🏾

[@aldyson3469]

Im at .43 engine off idle 4.2 in the 8s reved up

[@carolmeadows476]

Mine is 0 .00 does this mean maf is bad .

[@MechanicBundy]

Did it?

[@diego3ful]

Please someone, mine only gets to .534 at idle, it doubles that amout if i double rpm, is it bad,? Im getting lean codes

[@HVAC_Mechanic]

If it doubles with the RPM doubling, then it is usually good. Are you getting a MAF code? Lean codes can be difficult to troubleshoot since they can be caused by so many things. I made a full video on how to troubleshoot lean codes. Here is a link. kzbin.info/www/bejne/mGrCkIp9qqlgmsU

[@nobody1322]

I been plagued with p0101 code for 4 years, on the on position not running i’m getting 1.18g/s when starter and idle im getting 4.8g/s and at 2000 rpm i’m getting around 11g/s I don’t know if sensor is bad or good. my check engine light turns on usually stays on, but if i drive on highway for 30 min, turn off car turn car back on, the light will go off! sometimes stays off a few days sometimes a week but always comes back. any ideas ?

[@HVAC_Mechanic]

If the MAF sensor is good, I would test the wiring. It sounds like it is an intermittent issue, like a bad connection or a wire rubbing on something.

[@nobody1322]

@@HVAC_Mechanic I replaced my spark plugs and found oil in 2 spark plug coils. I put everything back together as i need my car but I’ll be replacing my valve covers in few weeks, curious if a leaky valve cover can cause P0101 too….

[@AkarKarim-xu2eg]

❤❤❤❤❤❤

[@LuwisRz]

Mine is at 15g/s at idle but i replaced it and its still reading high? Any idea?

[@HVAC_Mechanic]

I would test the wiring and be sure the connections are good. Also, an issue with the EGR valve can cause problems with some engines.

[@LuwisRz]

@@HVAC_Mechanic its a 4.6 ford engine through the scanner i have all my readings seem okay its just picking up alott of airflow somewhere

[@SilveradoUSA1]

Your engine Liters should come close to your MAF gps. For example, I have a 4.8L engine. My MAFF reading should be around 4.8 gps.

[@carobsessions4707]

My car shows 8.6 on avg grams/Sec When idle

[@denis4072]

You must got a monster underneath that hood.

[@twotoneprixflako956]

mine is 3.46

[@Mr.SoRandom]

My stays at 0.01

[@slowazzes1972]

Your probably in lbs/s rather than g/s

[@HEADBANGRR]

My scanner does not have grams per second. It has pounds per minute.

[@HEADBANGRR]

It was idling right around 800 and the reading was about 35 to 40. When I doubled the RPM The reading went to about 62. Does this mean my MAF is bad? Great info hank you

[@HVAC_Mechanic]

It is close to double, so likely good. There are other tests that can be done. I would clean it up and try again.

[@inmyexpression19]

Did you have a truck or car? Engins idle high at start up then go down after open loop

[@HEADBANGRR]

@@inmyexpression19 car