SR20DET Running REAL Rich

[24Zero]

I have replaced the heat temp sensor, checked the MAF and changed the fouled plugs. but for some reason the car is still dumping fuel and running really rich. If I get the car up to speed and keep it in boost it will run with no problems. but when the engine is not under a load it will stall and then not crank back. The original problem was it would not idle long enough to get the engine hot - therefore I checked and replace the heat temp sensor, checked and replaced the fouled plugs. I am almost certian that the MAF is working. The only other thing that I can think could be a problem is an O2 sensor - although functional - may be covered in soot and not reading.

Opinions?

Thanks

Jh