Hello again gentlemen. My father and I have finally got the Jeep running with the 350 chevy transplant.

I have a question though.

In the last few days it has developed a problem. While parked in idle the engine will surge and fade sometimes stalling out. It can run very rough after startup. The other day while driving it the idle slowly crept up to about 2500 RPMs causing the engine to overheat. Sometimes it will run fine with no problems. We hooked it up the the computer and it was throwing a code 44 lean (O2 sensor). We replaced the O2 sensor with no change. Fuel delivery seems to be fine. TPS is new. IAC is new. Injectors are new.

Does anyone else have any suggestions as to what could be causing this?

Thanks,
Dan