2016 Corolla engine light came on and has stayed on now for a month after clearing 3 times by disconnecting battery. Light came on and car wouldn't start after I topped off fuel at the pumps. I kept clicking nozzle to get all I could. Stupid, I know. Then the car wouldn't start. I waited several minutes and it barely started and engine light is on and car idles a bit rough. Autozone scanner shows P0171, P0441, P0455. Evap emission system leak gross leak/no flow, Bank 1 too lean, incorrect purge flow, etc. Now I know why they say don't top off fuel. Autozone says to buy MAF sensor for $102 but says it may or may not work. Any advice, guys?

 

I'm having the same issue, codes and all. mileage is also the same but mine is a 2018. what was your solution to the fix? did you buy a new charcoal canister? i replaced my purge valve and cleared the codes and they came back.

 

Would topping off fuel damage Mass Air Flow sensor?

 

No. There is no way that topping off the fuel would cause damage to the MAF sensor. Topping off the fuel could cause evap issues for sure, especially if fuel overflowed into the secondary pipes and into the charcoal canister, which could saturate the charcoal with fuel. Try removing some of the fuel (or driving until the fuel goes down).

P0171 is probably a separate issue from what happened after topping off the fuel.

 

Topping off fuel shouldn't do anything to MAF. It'll do everything else to the EVAP system. Don't top off. At the very least, clean the MAF if you suspect it. Clean the throttle body too while you are at it.

1. Buy MAF cleaner & throttle cleaner
2. Key OFF
3. Remove MAF
4. Spray MAF cleaner into MAF
5. Have someone assist you or place an heavy object on the accelerator pedal
6. This will actuate the throttle open to allow you to clean it
7. Clean/brush throttle with throttle cleaner
8. Reinstall everything
9. Unhook battery for more than 90 seconds
10. Start car (it won't start)
11. Start car again

 

First correct the P0441could be causing lean code.
Plug off the vacuum purge line from the intake to test.

 

Topping off your fuel tank will cause your Vacuum switching valve in your charcoal canister to get an error. Because it isn't able to vent properly.

But as others have mentioned, you need to take care of the other codes before you can look at the evap code.

 

P0441 and 0455 is likely because your gas cap did not seal. So when you parked the car and the emissions system checked for pressure leak it gave the code. Check your gas cap and play around with it. If the gasket is bad then replace.


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Couldn't all these codes be triggered by the canister having fuel in it? Right when I topped off fuel repeatedly and brought fuel up to the brim, the car wouldn't start and engine light came on. Engine light had never been on before for a vacuum leak or anything else. All the codes showed up when I tried to crank it up to leave gas station. Cranked after a few minutes but idled rough. I went by Autozone and had codes printed out. It seems likely to me that all these codes are from the evap system being damaged. This car only has 50000 miles on it. 2016. What about getting a canister from salvage yard? Should be good condition if low mileage car wrecked in the front. Could that solve problem? Thoughts? Thanks to all for you posts. Please don't leave me now.

 

This particular car has the vent valve built into canister so it would be a replacement also.

 

Is this a 2016 corolla? Then it needs to be moved to the 11th gen corolla forum.

 

Corolla John if you isolate the intake from the evap it will help pinpoint the problem.

 

Could you tell me more about how to do that? Thanks.

 

Locate the purge valve in the engine bay. It has a connection from the evap canister probably with a green top schrader valve in line. The other end of the purge valve goes to the intake.
The idea is to stop any fuel vapor from the canister being fed to the engine intake for testing purposes.

Right after you gas up there is a lot of fuel vapor that can cause engine to idle rough for a bit.
Could be caused by the purge valve opening more than it should or the evap system not absorbing the fuel vapor.
Pinching off or disconnecting/capping the purge valve from the engine intake should tell if either purge valve or evap system is causing rough idle.

The purge valve can be testing for leaks using a hand vacuum pump or trying to blow thru the valve.

 

Got it. I'll check it out. Thanks for taking the time to help.

 

@Corolla John What was you solution to this issue?

 

Moved to Gen 11 Corolla forum.

 

I had to replace the charcoal canister on my 10th Gen Corolla when something similar happened to me many years ago. That did take care of it and it was easy to replace. It cost me around $120.

 

I had to replace the canister too after topping off the fuel, easy job but be carful with the plastic connections, part cost about $150.00 i think

 

I had this same issue. 2015 Corolla. Couple years ago after topping off the tank car didn't start right away. That issue never seen again. Now car is almost stalling at stops. Finally I got a check engine light. Codes P0171, P0441, P0455 seen in techstream. I inspected the gas cap and it looked fine. I then cleaned it off and could blow air through it with no restriction. New cap cleared codes P0441, and P0455 and check engine light never came back. I still had idle issues whn coming to a stop. After scanning again with techstream I only had P0171 code but no check engine light. I contacted Corolla John and he confirmed EVAP purge valve fixed his issue in this thread. Pinching the tube at idle smoothed out the engine idle. I proceed to replace mine as well, no issues or code after replacement. Hope this helps others. Good luck

 

You already solved your issue… overfilling was the culprit

 

i have this issue on my 2017 corolla and lasted months. whenever fill car up with gas, it doesn't start. i basically have to hold the gas for 15 seconds then it will start (i guess lets trapped vapour to escape)
gas cap is fine.
replaced purge valve, codes went away then came back 4 weeks later.
then replaced charcoal canister, codes still there.
replaced purge valve again, codes went away for a couple months now they are back. after filling gas it does start fine though.

what should i do next??