Check Engine Light - Loose Gas Cap?

[Rolla Girl]

My check engine light has been coming on and turning off periodically. I checked the code and it says to check for a loose gas cap? Gas cap is tight and doesn't appear to be damaged in any way. Any idea what else could cause this code?

On a side note, I have been having sputtering problems and problems with auto-fill shutting off prematurely at the gas pump. Don't know if that's related.

Thanks!

PS... It's a 99 Corolla LE

[Flashmn]

yeah, its possible the gas cap is broken. Newer cars have emissions systems in them so vapours dont leak out.

[daniel2002p]

More than likely u just have a bad cap, try replacing it and see if it does the trick

D

[2001CorollaS]

I had same error, turned out my air filter housing wasn't sealed properly after changing air filter. From my understanding, any imperfect seal or kink in the system can very easily trigger this error. At least I have a a spare gas cap for when I forget it at the pump

[Rolla Girl]

Thanks for the feedback. I'll be sure to check the air filter housing before I buy that new gas cap!

[TRCar54]

You're car is OBD-II. There are at least 100 things that can set the Check Engine Light. AutoZone will scan the computer for codes at no charge. Write down what they tell you and report back to this forum or take it to your mechanic for his opinion.

The fuel cap is probably the only thing they mention in the owner's manual and it is just a warning to be sure to replace the cap securely.

One very common failure on Corollas is the EGR vacuum modulator valve. It's very easy to diagnose and the part is the same on any Toyota 4 cylinder from 1989 to I think 2000.

Good luck,
Jay in MA

Originally Posted by Rolla Girl

My check engine light has been coming on and turning off periodically. I checked the code and it says to check for a loose gas cap? Gas cap is tight and doesn't appear to be damaged in any way. Any idea what else could cause this code?

On a side note, I have been having sputtering problems and problems with auto-fill shutting off prematurely at the gas pump. Don't know if that's related.

Thanks!

PS... It's a 99 Corolla LE