I have a 95 Cavalier code 44 lean burn,with a bad hesitation and skipping feel on 1995 Chevrolet Cavalier

i unscrewed the o2 and drove it and the skip went away so I thought the cat was clogged so I screwed the o2 back in and the skip came back THEN the check engine light came on and it ran perfect like when the o2 was out. Someone has replaced the maf and egr. I have a snap on scanner and the o2 is switching pretty good, so this is throwing me for a loop like the computer may be bad, any ideas? Thanks Ken

Asked by for the 1995 Chevrolet Cavalier
what is the block learn and interrogator readings??

I found the problem, the thermostat was staying open telling the computer the engine was cold and dumping fuel which over a period of time fouled out the o2 sensor making it set a 44 code lean fuel but when I replaced the o2 the lean fuel code 45 appeared and I had to trace down the original problem which was causing all kinds of problems. The scanner was showing the temp at 130 -135f after running for hours and the temp gauge inside barely moved off the C. Sometimes its the basics we forget to check that will cause of a lot of head aches.