Check Engine Light? Codes P0446, P0455: What Causes a Car EVAP Code?

[@1AAuto]

√ *Watch the Video* √ *Buy The Part at 1A Auto* 1aau.to/m/Visit-1AAuto √ *Do it Yourself* √ *Save Money*

[@globalcommerce7654]

Should show a how to with a simple machine like this one: kzbin.info/www/bejne/aoOXgmyPYtiKY9U

[@alenjones5606]

Thanks so much. Best I’ve seen on the subject.

[@anthonytim89]

Can this have long term effects if gone unfixed?

[@ghettohey2388]

So my 2001 Ford F250 is needing the Fuel Vapor Tube Assembly replaced. My issue is I cant find an OE part to replace it with. The original tube assembly is 1/2 O.D. My question will it matter if I replace the Fuel Tube Assembly with a 3/8 O.D tube. If it will matter then whats your advice on fixing it. Im going to try some pull a part places

[@slchandymanssrvices]

My wife has a 2004 Pathfinder and she got a p0455 code (evap gross leak, large evap leak). Took to the dealer, they changed charcoal canister, vent valve, purge valve. Then p0455 code went away, then we got p1456 code (small evap leak). Dealer then changed gas cap, still got p1456 code. Took back to dealer after 1 month, they charged $185 diagnostic fee, said it was stuck vent valve. I researched, bought new fuel tank pressure sensor and vent valve. I installed both, still got p1456 code. On my work day off, I got under car, removed canister (I tested it, good). I noticed rubber hose coming from gas tank to canister was stretchy, so I bought new fuel hose. I cut back a little bit of the purge line rubber hose (it was stretchy). Also I bought new clamps (ones where you use screwdriver to tighten). Installed the new fuel hose (that connects to the canister), 3 new clamps for the 3 hoses that attach to the canister (vent, purge and fuel). Bingo!!! No more codes pop up (no more CEL check engine light). No more evap leaks. Hope this helps somebody.

[@Bohminator39]

Before you replace the valve or other components check your lines! lines are known to crack and dry rot and it will be a lot cheaper to fix.

[@gwendolynfloccari4927]

Great info. Calm clear description. I'm 75 year old woman trying figure out problem with my car. Mechanics charge so much so want to informed before take my car in. Wish I could still do simple maintenance one my car.

[@Txi-br1wb]

This is the best and clearest explanation I have seen of this. Thank you!

[@luiscarrasquillo8299]

I agree ☝️

[@jbarnes236]

Love your videos. You explain them in every day terms and do not make us feel inferior because of our lack of knowledge. Keep up the great work.

[@r.j.hadameo9501]

Awesome video, I was in the Automotive field for 25 years, mostly sales, but your videos always are easy to understand and always right on the money for the diagnostics he talks about.

[@boomertsm]

Last week, I got a PO446 code on my 2011 GMC Terrain 3.0L, Took it to my repair shop. They used smoke to identify an evap leak coming from my gas cap, so I ended up paying them $62 for a new gas cap, $220 overall for the repair (labor, part, and Credit Card processing fee!. After one week, the code reappeared, so I'm going back to the shop to see if the leak is coming from the gas cap area or other places. Thanks for the video. Well done.

[@hillcountrylivin]

One more tip on the gas cap, make sure it is clean and free of debris. If it's a bit dirty, just get some alcohol wipes and clean both the inside of the cap and the rim of the filler neck. That is one of the most common problems I've seen with the P0440 code

[@michaelballard3105]

This video explains a lot. I had 2 different shops that did smoke test, and neither could find it. The last shop suggested going to the dealer. I have a 2010 Jeep Grand Cherokee, and experience with what may be causing this small leak on this type of vehicle. Code is a po456. Some type of pump was replaced, which in this video I didn’t see or hear about a pump. It was done before the smoke test. I think the pump and labor was under 100, and they told me it may or may not be the problem. 2 smoke test later , I still have a problem.

[@cristianbivolan708]

As an old, retired electrical engineer I am very impressed with your teaching skills. Repairing my cars is one of my hobbies, but sometimes I am getting stuck into hidden specific manufacturing problems, like a fuse found under the wax paper insolation on a small AC transformer. Anyhow, I would greatly appreciate if you could help me troubleshoot my 2003 BMW 745Li, which started with not accepting more than 1/2 tank fuel (except when dispensing very, very little at the time), and lately getting the so popular check engine light on with the P0444 code on it. I disconnected and tested the purge valve and seems to be perfectly fine, opening and closing promptly when applying 12v to it. It may be that the purge valve intake hose having a small leak at the connection to the other hose going to the charcoal canister is triggering the P0444 code, but I do not believe this has anything to do with the tank not accepting more than half fuel. BTW, there is no pressure, nor vacuum at the filling cap after driving the car. Could you please feed back with your expertise/experience on this? Thanks a million, Chris

[@Alex-gj3ch]

I’m by no means a mechanic but I have a 2000 Ford ranger with P0455, a gross leak in the evap system. While doing some digging around I noticed my fuel filler tube was completely corroded and the rubber was very old. I’m planning on replacing this now and seeing if it can help keep fuel pressure due to the control valve and fix my rough start. While online I’ve seen people have the tube on their car be corroded as well or begin to leak gas whenever filling it up enough. It’s possible this is why you have to add the gas in very small spurts and why it doesn’t go past half

[@lo1234-w9r]

P0444 is “Evaporative Emission System Purge Control Valve Circuit Open.” You tested the valve itself so the circuit or the wire going to the valve has failed. Your charcoal canister is filled with gas because it's not being purged, which is why you are having trouble filling your gas tank. Of course I suspect you already know this.

[@dinonaccarato2989]

Just a note, You guys at 1A auto are definitely, #1A. I disassembled my 350 to remove my heads and assembled it just but watching your video. Just recently I watched the video for Evan code and again. Simple and thorough. Thanks guys Dino Edmonton, Ab. Canada

[@chadriddle3517]

Why this guy ever left 1A auto ? He was the best y’all have had !

[@austinhunt9520]

I love 1a auto, these are the exact the videos I look for when in need of help fixing my own vehicle

[@madchilll]

this was the most soothing and informative video.... came here to learn about the EVAP system, subscribed for the guy’s voice and great presentation. so chill! thank you!

[@1AAuto]

+madi c. Thanks for the feedback!

[@jacobdonnell2443]

1A You are gentlemen and Scholars.

[@thomaslaban5909]

I found it easier to take the bolt out and then remove the connections. Good video, helped me out.

[@everettbillingslea9021]

Extremely helpful. Now I know where to begin in solving my problem. Without this understanding it was hard to know where to begin.

[@1AAuto]

+Everett Billingslea Thanks for the feedback!

[@bigrad86]

Thank you for this simple and easy and right to the point video 👍

[@coolfool2100]

By far the best video on this issue I have ever seen

[@mrtrillionfold]

Thanks for the Video. It helps to easily understand the EVAP system.

[@1AAuto]

+Marcos Martinez Thanks for checking us out! 1AAuto.com

[@joemc111]

I got that dam engine light on, went to Auto Zone and got a report. P0443 your video helped me to understand thanks.

[@ilirbegaj5914]

Very simple and clear for eveybody that has some cars knowledges.Great job and thank you.

[@electrake2063]

@4:00, why do so many people get it wrong all the time! Every car is different! Jeeps and other Chrysler vehicles DO NOT COMMAND THE VENT TO OPEN! They have a switch that can detect if there is a vacuum on the system, only! If there is enough vacuum it will open and allow air INTO the system through the carbon filter, just based on the amount of vacuum, to draw the fumes into the intake Thru the carbon filter according to the purge solenoid duty cycle. Is there ANYONE out there that can stop oversimplifying how these things work! How many people have you led astray with bad and incomplete how-to videos?

[@josiah7068]

Diesel very good tips for checking the evap system on a car, however… I ran into the trouble of replacing the filler neck on my 04 trailblazer… using a Dorman part… come to find out these Filler necks do not seal to the GM gas cap.. took me a whole year to figure out what was wrong…. I could not find anyone who could check my gas cap for me…… I purchased another neck thinking I had a defective one as well as two caps…. When I attempted to apply pressure orally to the filler neck and found the gas cap leaked as if it was an open vent is when I realized I needed the factory jam part filler neck… and that’s how I got my check engine light off and cleared for inspection

[@shlink2]

Great video and explanation! Question! Can a evap vacuum leak, have enough effect, on the rest of the vacuum system, to cause the transmission to code and shift a little hard? I found my vacuum leak to be at the base of the filler neck on our 2004 Colorado!

[@genesssisss]

No one explains mechanical work like 1Aauto!!!!

[@1AAuto]

+genesssisss Thank you! We love empowering our customers and showing how to perform DIY auto repairs with our high-quality auto parts. 1aau.to/m/Shop-1AAuto-c

[@faizaanalap4]

your amazing calm soothing voice tone makes the audience understand and absorb information very easily. great teacher and presenter

[@1AAuto]

+faizaanalap4 Thank you! We love empowering our customers and showing how to perform DIY auto repairs with our high-quality auto parts. 1aau.to/m/Shop-1AAuto-c

[@robscites4561]

A concise yt video that explains what I needed. Didn't know that was a thing. Great video!

[@lynnesaro7772]

Exactly the video i needed. I think im having EVAP issues. The theory in the video is explained perfectly so i can understand how EVAP works.

[@1AAuto]

+Lynne Saro Thanks for checking us out. Shop for high quality auto parts on 1AAuto.com: 1aau.to/m/Shop-1AAuto-c

[@dman3349]

Great tone for teaching Bro! Keep up the great work!

[@1AAuto]

+D Man Thanks for the feedback!

[@jesusgallegos1090]

Excelente explicación, muy acertada y exacta, muchas gracias.

[@williampowers2997]

Wow! Great explanation. Less scary than I thought.

[@1AAuto]

+William Powers Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@gordhammond7105]

The explanation was crystal clear thanks.

[@barryteater1612]

Awesome video. Really explained the EVAP system well so I can start to have mine diagnosed and fixed.

[@1AAuto]

+Barry Teater Thanks for checking us out. Shop for high quality auto parts on 1AAuto.com: 1aau.to/m/Shop-1AAuto-c

[@macknumber9]

@@1AAuto How do you know how to test if your fix worked? Do you need a fancy scanner to get live data? Do you just delete code and wait to see if it comes back? Is there any live data I can check to see if the problem is resolved?

[@myisonu4639]

Glad i ran into this video, very informative and easy to understand.

[@hughmorris2008]

This video *really* helped me understand the evap system! Thanks

[@yolo-cars]

Thank you for this video! I got 97 W140 Benz and recently I got P0455 error and CEL. I'll try to check both purge valves (this car has two of them) and the gas cap. Other stuff I can't even touch since my garage is pretty narrow. Unfortunately, the charcoal canister is located behind the rear wheel liner. Can't even register the car while this CEL is present...

[@GrabinGears]

Just replaced my purge valve on my 4th Gen TL. I love your channel BTW

[@bartonblack7953]

Very easily and clearly explained. Thank you

[@marshmower]

I may have a leaky tank hose or breather. My gas cap used to go "pshh" when i removed it. No more. Evap solenoid alows flow when energised. Blocks flow when disconnected. I just unplugged it and the breather line. I no longer smell gasoline either when i stop. Gas mileage went up 5 mpg... I believe it was sucking lots of air through the tank somehow.

[@tymr.t3645]

Woow you broke that down 101 lesson Thank you for the information 👍

[@Shorty40101]

Would it do damage to your car if you clear the code and it doesn’t get changed ?

[@graffitticopie]

most clear explanation I every read for P0455!!!

[@1AAuto]

+wei Huang Thank you! We love empowering our customers and showing how to perform DIY auto repairs with our high-quality auto parts. 1aau.to/m/Shop-1AAuto-c

[@claztube]

I read that habitual 'Topping Off' your fuel tank can eventually render the charcoal canister ineffective. If this occurs would it cause an EVAP code?

[@Mountain-Man-3000]

Eventually it will if gas keeps getting into the charcoal canister. The charcoal will get saturated and will basically turn to mud, meaning vapor can't get through.

[@pedrovaldez9559]

I'm not a professional mechanic. As I've been learning through KZbin how to fix my vehicle I've learned that topping off your gas tank is bad. Right now my 2006 avalanche isn't allowing me to put in gas properly. I spend like 20-30 minutes at the pump to fill up. That's because one of my fuel lines is clogged up with charcoal pellets. When I replaced my canister I cut the old one open and it filled with charcoal pellets. So, that's what happens when you too off the tank. People want that little extra more fuel, but it'll cost you more money in the long run when you have to do repairs.

[@DD-ud8oz]

Great video! What if your vehicle doesn't have a gas cap?

[@endlessexotik770]

Best and clearest explanation You rock

[@Buellercom]

Thank you!! Just got the code today and now i know what to look for.

[@1AAuto]

+Joseph F Thanks for checking us out! 1aau.to/m/Shop-1AAuto-c

[@Emilthehun]

Awesome thank you. My vorvette has a code for blocked vent . Replaced the vent solenoid, and still has the code come back.

[@hajrudinkavazovic2231]

Vorvette lol 😂

[@nielsboegholm9807]

Thanks for a good down to earth explanation and ideas for fault finding.

[@ramesherrabolu1590]

Your explanation was clear and good. Keep up the good work

[@TeslaBoy123]

Thanks a lot u are a real teacher 👍👍👍👍

[@ro-landocalrissian4633]

Would you get the same code for a bad gas cap as you would for a faulty evap canister?

[@michiganborn8303]

My brother just called me about his evap system on his '14 Ram 1500 having problems. I asked him if he has a habit of constantly clicking past the automatic shutoff while at the gas pump. He said yes and I told him to tell that shop you do this so they know what to look for. Then I told him he only needs 1 or 2 clicks not 20 past the automatic shutoff.

[@toml3651]

The purge valve and related system is easy to understand, when it opens the fumes are vacuumed into the intake stream. Tell me more about the vent: does it just vent to outside air or is it terminated in the system somewhere? Your diagram doesn't show exactly what it does.

[@davidtunstall7242]

Thanks you explained how the system works

[@serious460]

i love thos type of videos 1 a auto parts good work

[@1AAuto]

Serious Thanks for watching!

[@PhilAVega]

Thank you 👍👍 2021 Ford Eco sport Big help for me

[@williammaes5655]

For a couple weeks, I smell gas in my garage. There are no leaks under the truck. Would a problem in the system you describe cause this gas smell? How about a bad/cracked canister? What are the first things you'd check?

[@teresacook3724]

Thankyou, I have a large emission leak on my 2020 Buick envision…. Can’t get in unti Dec 6th…. My car never had a gas cap only a door

[@ElflacoColl]

I already did the change of the gas cap and didn't work, today I changed the purge valve and had drove my car for 15 miles and the light stills on, should I wait a few miles more or should I clear the code with a scanner ? Thanks !

[@punkeyengineer]

This is just perfect explanation!

[@m1cajah]

Persistent P0455 code. Replaced gas cap twice. Looks like I’m going to have to try the “replace until it’s fixed route” to find the issue. No access to an evap smoke machine. What, after the gas cap, is the next thing I should try? I do have a faint gas smell. 2007 Tahoe.

[@wheresmytacos3661]

One thing I did to help find leak after spraying everything with soap and water is I duct taped gas cap opening after removing the cap. Poked a little hole used compressed air in filler neck

[@JAYBOLA1]

Can i just block off and delete the purge valve? I want to clean up the engine bay

[@dalelange845]

Well done... Great informative video.

[@fredcastro6343]

Very clear and accurate! Thank you so much!

[@bestgirlsdad]

Thanks for the good video. Very clear, and now I understand. Have a blessed day.

[@totbob8947]

Thank you for this detail. What a kind of signal electric to command valve of purge ( it is square wave or analog wave

[@firstnamelastname6193]

thank you for taking the time to explain everything!!!

[@stevewilliams4777]

You made it clear that the purge valve and vent control are in 2 different locations but are they the same part? I can only find vent control replacement on your website for 2012 altima 3.5

[@curedham2963]

ive replaced the purge valve years ago and now the gas cap today and at some point the vent valve today. Hopefully this does the trick or else its the connector for the damn purge valve thats causing it to stay open.

[@azzammeeralam7182]

Great explanation. My 2015 Mini F56 B38 engine has code 190302: "fuel tank ventilation air system micro leak; leakage greater than 0.5mm". Symptoms: rough idle, and noticeable shaking while driving and longer start up after refueling (~5 seconds). Ordered purge valve hoping it will fix the problem. Let me know if anyone thinks it's something else, but I'm starting with purge valve since it's easier to access. Next on my list are the leak detection module and vent valve.

[@mikeb4062]

Any luck with the purge valve?

[@macknumber9]

How do you know how to test if your fix worked? Do you need a fancy scanner to get live data? Do you just delete code and wait to see if it comes back? Is there any live data I can check to see if the problem is resolved?

[@javierbotello5507]

Good job my friend

[@DanielRodriguez-gd3hi]

My car has the P0455 code. It also has been struggling to turn on sometimes. It had a new cas cap and new purge valve. Could It be struggling to turn on because of pressure in the vaccuum potentially caused by a bad vent?

[@nickayivor8432]

Happy Christmas 🎄 Thanks 👍 From Nick Ayivor from London England UK 🇬🇧

[@bobbyrayparris6711]

My Charcoal canister was putting charcoal in my purge valve which was stopping at up so I took the charcoal canister off and install a new purge valve.. do I need to keep the hose in from the charcoal canister or can I take it off

[@EvzenKovar-i5p]

So, if a vehicle sits for an extended period of time, our fuel systems work just like in the old days with vapors sent to the atmosphere through the EVAP vent? All things equal, do most vehicle fuel tanks not generate enough gas vapors over an evening/night to put vapors directly into the atmosphere?

[@codyshuey258]

Okay so 2 questions.. Would a blocked purge vent affect gas mileage at all? And also, does this cause rough idling?

[@TheSleepingonit]

My truck is registered where emissions is not done, will taking out the evap system make it run better?

[@franksmith2984]

Im buying your parts now. Totally swung me

[@shamanismtarotnhealing]

I have lean codes on my vehicle but it's been pressure tested & no leaks, the evap shows fail when I put it on a diagnostics machine, but the scan tool sais p0171& 174 can a bad vent solenoid cuase a lean code if it is stuck open, or is there any other areas that would cuase a lean code? I've taken it to a mechanic several times & he said the lean code is coming from a pressure sensor he has never heard of on the evap system & after testing the purge valve & the on board diagnostics shows the purge valve opening when called for but shows failed evap system so my best guess would be the vent solenoid. Any advice would be greatly appreciated thank you

[@javee-th5no]

If I found lil black charcoal pebbles in Purge Valve Solenoid, is that from the purge valve canister or from the charcoal Vapor Canister? Thanks nd great video!

[@vincentbarkley9121]

Great, clear and helpful video. Thank you.

[@blarpieman]

could a vent valve hose clog cause pressure to rise making it difficult to fill the tank creating a check engine light and hesitation near idle? Your awesome!

[@adriancaleanu]

I have a 2011 Jetta. The original gas cap doesn’t click any more. Then I bought a brand new cap which also doesn’t click. Then I bought a used gas cap which also doesn’t click. I still have the check engine and I’m out of ideas. Could it be a problem with the tank nozzle?? Thank you.

[@Blossannova]

So would the purge valve not working also cause random misfires? Sense it’s not closing in time to keep the gasses going to the cylinder

[@JohnDoesItAll]

Excellent explanation!

[@sovvers1752]

Sir, I overfilled my gas tank from a faulty pump, just a little, not much at all. It caused an EVAP code to pop up (2016 Chevy Cruze), someone told me I can take an air hose, blow out the excess gas, reset the code and be fine. My question is- can I blow that out? and where from?

[@samuelanderson1415]

Thanks so much you all are the best I asked for a video about this and here it is thank you thank you

[@abisismael1343]

Great explainations. Thanks !

[@techFPV5964]

I have a question my computer is throwing a P0455 and the air gas cap is tight so i took it to the shop and the guy said he would have to perform a smake text for $900.00, not including the part does thart sound. Does that sound right to you? Thanks bro!! Thanks a lot for for your time. Harry Lato!

[@Leo-jf1pc]

Forgot to mention about the “evap pressure sensor”. Bad evap pressure sensor could also cause an evap code if it’s malfunctioning. But good explanation.

[@1AAuto]

+Leo Thanks for the feedback!

[@peteryosilee6787]

Very informative and helpful. Thanks for sharing.

[@hsiaolingsu6930]

Would this apply to older and newer vehicles as well?

[@meinihongohanaso7843]

Even I understood, thank you for making this video.

[@vanrey36]

I appreciate your explanation

[@Alsan15]

I have a 2002 dodge ram1500 it kinda hesitates too start and it has check engine light saying something about changing evap hoses and it also revs it self when on could the purge valve be the issue ?

[@franko.5609]

Our Toyota Corolla 2016 runs fine but got a check engine light. We turned on the car and we removed the switch (from the pcm) that goes to the purge valve and put it back. It then resets the check engine light, but just for a few days. Do you think the issue is the purge valve why we get the check engine light? Code is P2024.