I would like to thank everyone in advance for any help/comments they can leave towards my situation. I have a 1994 Acura Integra GSR with most of a stage II turbonetics turbo kit installed. It also has a Greddy EvoII exhaust and a 2000W stereo system installed (may be important). I recently had new rims and tires installed on my car and also had them throw the exhaust on at the same time. Within three days of getting the car back I noticed an absence of power below 5k rpms and a discomforting sputtering between 1k and 6k RPMs at any level of acceleration with the exception of maintaining speed. I replaced the plugs as soon as i noticed the problem with some NGK plugs i had bought previously. I forgot to mention this, but the car was totalled and rebuilt over the course of the past 2 years so it has been sitting for quite some time. As far as the turbo kit is concerned, I have installed all of the intercooler piping and mounted all of the electrical components, but besides being grounded none of the wiring is hooked up. I took the turbo off and disconnected the wiring because it had locked up and i need to have it rebuilt. The stock headers and cat are hooked up but from the cat back it is all brand new. My revs also drop to near stalling out everytime i stop and jump around between 0-1.5k when i am going slow or just turn it on (problem starts about 30sec-1min after starting the car.) I am getting spark on all the plugs and haven't seen a CEL as of writing this post. The car is also overheating somewhat but the cause of this is unrelated to the problem and more related to sitting for 24 straight months. However, the overheating could have something to do with the poor performance. The fuel filter, ignition coil, distributor cap, and rotor while around 2 years old have less than 200 miles on it, most of which have been within the last week. The old plugs showed no signs of oil, and the electrodes were very white. The car has 150k+ miles on it but i knew the owner and he did all of the scheduled maintence atleast twice as often as it needed to be done. I have checked the majority of the vacuum lines and they appear to be intact and w/o leaks.
I am thinking it may be an 02 sensor since it gets much much worse at operating temperature but am confused since i am led to believe that the CEL would be on if this was the case. If anyone has any clues as to what my problem might be or have had this happen to them please reply as it will be greatly appreciated. Thank you very much.

 

Have you tried a different cat or no cat at all. Could be the problem.

 

What were you using for engine management with the turbo and is all that removed and reverted to stock now that the turbo is removed and a header is being run?