Originally Posted by willwren

The first thing to do for a performance chip is remove the Nitro Chip that you have:
http://cgi.ebay.com/ebaymotors/1991-...temZ8021425377
Which you paid almost $30 (probably more with shipping) and is nothing but a 25 cent
resistor in a box with two wires and doesn't add 20hp like they claim. It might be half a
horsepower at best. Possibly 5 for the first half hour, then it fixes itself.

Their claims are actually quite wrong and they clearly don't understand how the PCM'* in
these engines work. That 'chip' can't change the AFR for more than a few seconds
before the O2 sensor corrects it. It CAN increase timing slightly in a pre-OBD2 car without
a MAP sensor. But again, it'* worthless.

Your only PCM option is www.gmtuners.com and you better REALLY have a solid
understanding of shift points and power curves. A dyno run is a necessity for the info
you need to have a chip programmed.