4.2LV8AUDI

I occasionally get a steady CEL, and usually has to do with the o2 sensor. It goes away after a drive or two. This morning I start up the car, and it starts really rough, then idles rough. CEL starts blinking and I immediately turn the car off. I let it sit for a while, then try again. Starts fine, no CEL, running as normal as can be. I know the blinking CEL, and the roughness can be a sign of a mis-fire. Should I still be concerned, now that it is running fine?

Press

vag com is your friend

btruby

j/k good luck.

Raudi_6 akaDeutschMF

Thats an awesome sig!

BoneDaddy

2nd

ga_mueller

burn out your cats, etc. It will only happen with a huge misfire. I know; having screwed up the plug wires on my wife's 2.8Q, two cylinders misfiring, then the blinking CEL. Now I have a rattling cat.

CALL AAA

I reset it wit VAG com to see if it would clear, and although it stopped blinking, the CEL stayed on. I brought it to the dealer, and they replaced the plugs as part of normal service. The light is out now, and it runs fine. But the codes I had were for misfires, with no indication of an EGT sensor.

joegoalguy

I bought my 2.7t with 99,000 mi on it. The CEL light was on. I, too, thought it was just an O2 sensor. When I took her in at 100,000 for the timing belt change-out we discovered that it had actually "skipped a tooth" and had been misfiring.

BoneDaddy

it happened to me once last year, misfires, not happened since

nickwh

In my experience, this is the sign of a failing ignition coil(s).