A8Kevin97

I have a 1997 A8 and I had one of the rear O2 sensor replaced because the engine light came on and because of the bad gas mileage. I had it replace and is driving fine.....then after 50 miles the light came back on then 2 days later all day the light wasn't on.....so I though it's fixed. Then today the light came on!

Any suggestions on things to solve this? The dealership said it could be as simple as just filling it up with gas that could cause the light to come on!

KEvin

JimR

That's why we're always talking about VAG-COM.

Without that, you're stumbling blindly in the dark.

marcodant

also look around, i had the same exact issue and I pulled my code it was running lean bank 1, bank2 and other strange things, when I followed the bently for days and weeks I tested everything and still was looking. finally founb out I had a air leak in the intake manifold. Because of that I was getting strange codes, readings on other sensors including the O2 sensors. The way I found the leak was with the eng running squirt something like wd40 or water and listen for it to suck into the intake. I spent a long time looking at hoses, changing them, and testing all kinds of things. it will drive you nuts. But boy will you learn lots about the car.

ohbw

I find it very restful to place a small photograph of a naked woman over mine and checks the codes at my leisure.