i have a 91 firebird, 3.1 liter that failed an emissions test. its sending out codes 32, 44, and 45 (egr, O2 sensor lean, and rich). it seems to run great, except for when i disconnect and reconnect the battery to clear the codes, then it runs like crap until it seems to clear itself and the codes come back. I replaced the egr and gave it new plugs, wires, cap and rotor, and pcv valve, and still the same. is the ECM possibly screwed up, or should i maybe try a cat. converter next? i think the ECM is correcting the air/fuel mixture and the battery has been connected, since it seems to run rough after the trouble codes are cleared. the car is clean, stock, and runs great, so besides the codes, i can't see why it's failing.

 

To start out I would find someone with a pro scan tool or auto x-ray to check and make sure that your o2 sensors are working properly and in spec. If there all in order then I would check egr actuator.
The cat would have nothing to do with the car entering loop home mode ( what makes your car run better after resetting the codes and still having a problem) A sort of safety feature..

 

i think i got it taken care of, i gave it a full tune up (plugs and wires, distributor cap and rotor, pcv valve, air filter), and the codes have not come back, and disconnecting the battery no longer effects how it runs. i still failed emissions after the tune up, so i have since replaced the cat converter as well. now i have to get another emissions test...