cheesypoof

MY 2001 1.8TQ has started having a very rough idle. Runs fine and has plenty of power at higher RPM.

Vag-com reports the following codes:

16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-10 - - - Intermittent
16685 - Cylinder 1 Misfire Detected
P0301 - 35-10 - - - Intermittent
17584 - Bank1: O2S (Lambda) Correction Behind Catalyst: Control Limit Reached
P1176 - 35-00 - -
16686 - Cylinder 2 Misfire Detected
P0302 - 35-10 - - - Intermittent
16688 - Cylinder 4 Misfire Detected
P0304 - 35-10 - - - Intermittent


Cleared codes, ran engine for 2 minutes and got the same codes:
16684 - Random/Multiple Cylinder Misfire Detected
P0300 - 35-00 - -
16685 - Cylinder 1 Misfire Detected
P0301 - 35-00 - -
16688 - Cylinder 4 Misfire Detected
P0304 - 35-00 - -
16686 - Cylinder 2 Misfire Detected
P0302 - 35-00 - -


Based on my searching, it sounds like it could be a coil pack problem, but what are the chances that I would get 3 bad coil packs at once????
I will try moving #3 (which seems to be the only good cylinder) around and see if the codes follow coil packs 1, 2, 4.

Should I look at something else, or go ahead and replace all four coil packs?

I know that the coil packs were replaced via recall way back in 2003, but I seem to remember that there was a second recall two years ago that I ignored? Does anyone know if there was a second coil pack recall, or is it just wishful thinking?

MikekiM@PureMS

If the control limit is reached on the O2, then it would sound more like a lean misfire. Check for vacuum leaks in the breather system.

cheesypoof

Turns out the coil packs were covered by a recall, so Audi replaced all four for free. Didn't help the rough idle problem. I'll check for vacuum leaks next.