I'm having troubles with a 16v wagon I just bought (199,000 km). She starts fine ,runs fine for a few moments (30 seconds) then starts to hunt, followed by rough idling. acceleration is bumpy too. She seems to run very rich. using the code reader at this point in time, shows no faults (1-1-1).
There was a crack (exh leak) in the cat conv. so I replaced it along with the o2 sensor. I also cleaned out the oil breather. The fuel pressure regulator looks very new too. I cleaned out the map sensor with spray cleaner and checked all the vacuum lines etc.. for condition/connection.
The problem is still just as bad.
The old o2 sensor was covered with sooty carbon along with the inside of the old cat conv and tailpipe.
I'd love to be able to adjust the mixture but there is no where to do that I think).

Any tips or info on this prob would be much appreciated.