i have a mail order tune on a 383 w/ le2 h/c package with about 500 miles car has ran great but i had recently blown my rear and decided to upgrade with a moser 12 bolt and 4:10 gears. so i decided to calibrate my speedometer through my hypertech power programer yesterday so i started it up today and now the motor runs like crap and i have a hard time starting it. it idle is also lower and wants to stall out. is it possible the hypertech messed with the mail order tune?

 

Depending on what you actually told the Hypertech to do, yes.

 

im pretty sure i only told it to adjust for diffrent tire height and for rear gear ratio but if its messed up will the person who i sent the pcm out to be able to fix it?

 

Why can't you pull the hypercrap tune out of it? Did the box save the 383 tune as the original?

 

im not sure what it did but i just sent it back to stock and im going to send out my pcm again

 

I wonder if the Hypertech made it's changes based on your tune, or if it uses a "stock base flash" and adjusts that internally then loads that to your car, replacing your 383 tune.

Sucks that it happened, but I've heard horror stories of people trying to use both the Hypertech and a custom tune and having problems with messed up PCMs.

Good luck getting it straightened out!