Alright heres the story, I have a 92' RS with the 305 tbi (lo3 I think the code is) Anyway where can I get a Factory chip for it?? I recently found out that the car has a hypertech thermomaster chip in it. After reading up on the chip I found it is supposed to be run with premium fuel to work right. With fuel prices at $2.89 for premium I am trying to save a few MPG. I appreciate any help anyone can give me.

 

A few options, search the classifieds here...GM parts direct, your local GM dealer, etc.

IIRC, my dealer wanted 70 or 80 for a factory chip, GM partsdirect was about 60+ shipping...

Instead I went to ebay and found a ECM w/chip for 50+plus shipping.

Ya know what, I have one you're welcome to borrow if you can get someone to copy it, then just send it back to me.

 

The whole needing premium fuel for that chip is a load of crap! They add 2 or 3 degrees of timing in a couple of spots, and a hair more fuel.

The difference is so small, its ridiculous. You're fine with any octane provided your car is in good mechanical condition.