More TPS on 91 PA

Ny TPS problem on the 91 PA have not gone away. I bought a new TPS from Pep Boys, and put it on the car and could not get ANY voltage readings on it. I put the old one back on and finally got it adjusted out to 0.039 Volts, but the light still comes on, but will go off while driving. Car runs great and just passed inspection here in Texas. Clouple of questions please,
1. I had to take the entire throttle body off the car to get to the TPS. Can you get proper voltage adjustment with the TB off the car? I assume you still need to have the wiring hooked up. I have an Auto XRay 6000 diagonstic scanner that tells me the voltage of the TPS
2. Should I go to GM to get the TPS or is one from Napa, Pep Boys, etc.. of the same quality.
Are there any tricks to getting this set accurately?

You are close enough for the base setting( .33-.46) so that is not the issue, what are the performance issues here? What is the code, does the tps seem to transition to full throttle smoothly.

Code is a 22, which is TPS voltage low. Car seems to run just fine, no performance issues at all that I can determine. Sometimes the light may not come on for a couple days, other times is may come on several times in a day, but like I said, there doesn't seem to be any performance issues.

The pcm gages this based on engine load and what it assumes the throttle opening should be. Try cleaning the maf, use CRC maf cleaner. Is this a C engine or an L engine, look at the 8th digit in the vin.

Max, this is an "L" engine.

Check this link for parameters for that code. http://www.troublecodes.net/GM/91_38L.shtml

Thanks a lot, I am going to hook up my scanner to it tomorrow and watch the readouts as I drive down the road to see what the voltage is between 50 and 60 MPH (actually, I'll get my wife to drive and I watch the scanner). I also plan to clean the MAF, will the CRC hurt the screen at the end of the MAF?

Finally got my TPS problem cured, the computer needed replacing. Runs great now. Thanks for all your help.