larry brim

I have a non-Vette related question. My 03 CTS displays "check gas cap" on the info screen when I make stops sometimes. The cap's been replaced, the check engine code reads that the 02 sensors are bad, they've been replaced, but the check engine light came on again and the check gas display is back. Any suggestions, thnx.

stingray76l82

Gts

jdot

My check engine light kept coming on in my 04 Vette so I took it to local Chevy dealership and the code said replace gas cap and that solved MY problem. Good luck

Tron Z

Check Gas Cap - AKA you have a large evaps leak. Could be the gas cap, filler neck, fuel tank, fuel tank fittings, or various hoses. Unless you have an actual leak (check for fuel stains, not just a puddle under the car) diagnosing this type of problem can be very tedious and could require special equipment.

By the way, the ECM can not diagnose a faulty component. It can only report that the output from the component is either out or range, or inconsistent with the feedback from other components. That does not necessarily mean that the component is bad.

larry brim

Thanks for the info, this gives me some info to take to a technician and I won't be totally blind when I take the car for service.

8VETTE7

You need a dealer to change the gas cap?????????????????????

molon labe

Gas cap is usually the culprit, so make sure you're tightening the cap completely. Also make sure the o-ring is still on the cap, and check to see if the cap has been dropped or damaged.

Then use a code reader to see if the codes are current or pending. Clear the codes, make sure the gas cap is always tight, and see if they return.

dmaxx3500

just take the cap,spray it with ''simple green'' and rinse it out with hot water,