OK I'm about ready to execute this car. 1998 Audi A4 2.8. Went down the other day to get it smogged past no problems all emissions in average range.

Got home gave it a bath and noticed it was leaking water into the driver side floor board. Found that the ECU box gasket (between box and firewall) was FUBAR. So I fixed that, had to pull the battery, pull up carpet, air dried. Got car put all back together one small wrinkle while moving the ECU box around I scrapped a wire had to use liquid electrical tape to repair it wasn't bad just a little exposed wire.

I take it out for a test drive and it is shift hard into third, for a bit that settled down now is only doing it when I get on it medium to hard the rest of the time it shifts no problem.

THEN it starts to shutter and cut out CEL light comes on. I get home check with OBD reader says PO301, misfire in cylinder 1. I clear it and take it back to see if it was a fluke remember no problems a couple days ago when I parked it. Get half a block from the house and it almost dies stuttering and coughing, I get it home and it throws PO300, 301 303, 300,301,303.

I believe this means multiple misfires cylinder 1 and 3 right.

So tell me what you think. could I just need new plugs to be honest I don't know when they were changed last. The wires look pretty good and like I said no problems before I had to pull the ECU?????

Thanks for reading and providing your responses.

 

Take a look at your plugs. If they are really bad, replace them. That's the cheapest fix possible, and by the sounds of things it needs to be done anyway. I've pulled my ECU out numerous times and never had any issues like this, so simply moving it shouldn't have done anything. Then again, sometimes these A4s can surprise us all. Try the plugs, then let us know.

 

I pulled the old plugs out, cleaned them and the wires, turns out there was some water in the holes from cleaning, took it out and drove it, seems to be a lot better, still had a PO303 under a real heavy load, but have not been able to make it repeat. Think I'm going to replace the plugs anyway just to make sure, if they are bad a cleaning will only last a short time.

 

Hope that solves it! Let us know if the problem persists.

 

Could also simply need a throttle body alignment, I do ti everytime I disconnect the battery

 

Thanks all, I don't have the VAG-Com to do the throttle body alignment, I'm going to take it for a ride this morning to see if the hard shifting has corrected after and overnight sit.