I have a 2003 A4 1.8t quattro.

I am getting a misfire in cylinder 3. Freeze frame data shows that it only occurs in open loop cold start. There's no misfiring while I'm driving either. Fuel trims look normal. However the fuel status changes to OL- drive on decelaration.

To troubleshoot I replaced

#3 spark plug with #4 -- Misfire Cyl. 3

#3 coil with #4 -- Misfire Cyl. 3

#3 injector with #4 -- Misfire Cyl. 3

I did a search and found it might be the diverter valve or wiring harness to the coil. Any ideas?

 

Start by changing the coils. All of them. The coils were on recall. You may be able to get them no cost

 

The coil was already changed by an independent shop. It didn't solve the problem. Hopefully someone here can help me out so I don't waste anymore money.

 

bump. I still have the cold start misfire.

 

check the wiring to the coil pack, it likes to melt or the insulation gets brittle and cracks and the wires short out

 

when you take out the coil packs, take a look down to see if you have any oil around the spark plug.. I did on my 3.2L on cylinder 3 (v6 engine) - and solved it with a new valve cover gasket and about an hour of my own labour. on the 1.8t it should be about 45 minutes