2002 A4 quattro 111,000miles. Catalytic converters replaced sometime in late 2007 around 103,000 miles. Lately, the check engine light pops on - car runs fine. Have had looked at - diagnostics run (paid approx $80 each time), only to be told that nothing can be found. I've discovered that opening and closing fuel door will get the light to turn off (sometimes I have to do it with car running, sometimes before I start car after sitting for a while, sometimes it's a combination). As you can imagine, though - it's a bit annoying to have that crucial light go off and not really know if it's warning something valid (especially since it may take a few attempts with the fuel door and a couple of ignitions on/off to shut off).

Any thoughts about this so that I don't keep going in and paying $80 for a computer to tell some tech that my car is fine.... Thanks

 

First off you can have your codes read for FREE at any local Advance, Auto Zone, Pep boys, etc. Or buy one for less then 200.00 and pull your own codes. Make sure you are clicking the fuel cap all the way closed or try replcing it with someone elses that will send a code to. but if your engine light turns on you do have a code. Have it scanned while the engine light is on.

 

gas cap is turned until it clicks. engine light comes on at random intervals with no relationship to having just put gas in car or opened/closed gas cap. diagnostics have been run when light was on - was told there was no identified malfunction. wondering if this is a common problem after the catalytic converters are replaced (although it's been well over a year since having them replaced before the problem began) or if it's possibly a short in the system throwing the light. it was suggested to us that if it continues we should have the cat system looked at again (different euro shop running diagnostic than one that installed cat system b/c of proximity)