# Can a bad gas cap cause idle problems?



## sfhellwig (Feb 4, 2003)

I have been searching high and low for a fix to my severe idle problem. In my searching I have seen reference to running the car with the gas cap off and that throwing a code. Is there any way the cap could leak just a little and not throw a code? Does not having the cap on even affect the way the car runs?


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## bahearn (Jul 15, 2002)

The cap must be tight or your OBDII system will show an evaporative emissions leak CEL.


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## sfhellwig (Feb 4, 2003)

Good to know what exactly its called. What I was wondering was if the cap leaks a little, can it affect the way the car runs without throwing a code. I asume not or else the code would be pretty well useless.


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## bahearn (Jul 15, 2002)

Nope, the car will run fine.


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## sfhellwig (Feb 4, 2003)

Thank you for the info. I have since found my idle problem to be the EGR valve but am collecting my little book of facts for future diagnostics.


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