Is my ICM or coil packs failing?
 

Is there a such thing as "WEAK ICM" or "WEAK COIL PACKS". Does the ICM or the Coil packs run weak or just fail flat dead. Is there "IN BETWEENS." Can both of these perform poorly or do they just 'work' or 'don't work'? I'm having misfire issues. Some people say it could be a weak ignition control module/coil packs.
codes are: (P0134: O2 sensor -no activity detected) and (P0301/P0304:Intermittent misfire detected).

Re: Is my ICM or coil packs failing?
 

What car you have? 1.8 or 2.8? they are diff. you'd better check the spark wire and plug first. for the O2 sensor, looks need a replacement, but still check the wire first. If you have vag-com cable, you can even check the life of the O2 sensor and cat remain.

Re: Is my ICM or coil packs failing?
 

I't 1.8t. I think my thermostat was stuck open. I installed a new thermostat last week. That was probably generating the O2 sensor code. The MIL hasn't come on ever since I've changed the thermo. But it still shakes at idle, probably due to misfires. I put new plugs in and the wires seems to be in good condition. No cracks or deterioration.

Re: Is my ICM or coil packs failing?
 

The 1.8T runs HOT. Really hot. That's why you hear of so many coil pack issues.

Mine were "weakened" and then started failing one by one after I did my Revo software flash, probably from the extra strain on the engine. The car would stutter and shake at idle, and when I drove it would "sort of work" for a few seconds and then start misfiring again.

The fix was to replace all the coil packs (I'd suggest for you one by one though) with aftermarket STI coil packs.

Re: Is my ICM or coil packs failing?
 

The winner was a dirty fuel injector...causing misfires and shakes. It run very smooth now. No more trouble codes.
....decided to a follow up...after a few months though.