Ok so here is what is going on. It all started a few days ago when I went out to my car and started it, ok I got a CEL flashing, which included lots of shaking and studdering at idle and while driving. So I went on the internet and studied up on what could be wrong, well I found out that it could be anything from coil packs to injectors to a clogged air filter. This is where it gets wierd I bought four new coils installed them started the car and still a flashing cel, oh and I replaced all 4 spark plugs also. Then I tried switching all of the packs around and seeing if a new cylinder started misfiring, and once again no luck still the 4th cylinder. So my dad and I decided to drop the car off at the local mechanic shop, and for 65 dollars I was told that the ecu wouldn't send a signal to the fourth cylinder, and that their machine couldnt read all of the codes yadda yadda yadda ok vag-com is what I need. So now I have ordered the vag-com cable off of ebay and thats coming this week but the funny thing is yesterday I got a new ecu I just bought off of audizine and I replaced the other one with this one and still a missfire on the fourth cylinder(p0304 I think is the code). So can anyone think of what it could be??? I am so frustrated right now.

 

A flashing CEL is an active misfire, which is why your car was shaking. Do not drive or continue to run the engine in this condition. When you put tgenew plugs in, did you ensure they were gapped to .032" (or .028" if you are chipped)? That's important. Second, if you just got a new ECU from someone, it's likely that the caps are drained and the car needs time to power up and let the computer learn, so some issues may be stemming from that.

But let's assume plug gap is fine - swapping coil packs didn't move the misfire so they're likely not the cause. It's possible that the ICM is bad. If I recall correctly, some 1.8 motors have a separate ICM and sone have it integrated into the ECU (1.t guys please correct me if I'm wrong - I have a 30v so I'm not as up to speed as you are on the 1.8T).

I'd let the car run a bit as long as it isn't misfiring, and then take some gentle, no-boost drives to acclimate the ECU, and see if it stabilizes. If someone near you has VagCom (you really should fill in your location on the User CP), maybe they can then clear the codes and see what comes back.

 

Sorry I live in milwaukee wisconsin and I know a guy about 2 miles away who has it but my vag-com cable will be coming by friday.

 

think I know what is wrong and please correct me but i did the cone filter mod for kicks and giggles but didnt know much about the ICM and that it needed to be heatsinked and such because it runs so hot, so could it be shot or if I heat sink it will it be fine?