to start off my father has been aservice manager at a chevy dealership for 18 years now.Everybody wants to know if the tech2 will pickup the the tune, the answer is no.Today my father and Ihooked up the tech2 and went for a drive ,he checked every possible reading and not one reading was out of wack.This is proof that no dealer can tell whether you have a tune or not unless you tell them.This is something my dad wanted to do before we decided to send back the factory pcm just in case.Now I will send back the old pcm.I hope this helps everybody who was holding out on getting a tune.Also according to the tech2 it showed that my truck was putting out 400 ft lbs of torque,I know it`s not a dyno but my dad said he has never seen the torque that high on any stock silverado, so he`s thinking atleast a gain of 35 ft lbs or more of torque at the flywheel.

 

The Tech 2 is not able to read aftermarket programs. However, the tech can download your program into the Tech 2 and go the the desktop that every shop has. The desktop is used to get the lastest updates from GM. Via the phoneline the Tech 2 will comunicate with GM and see if the PCM has any updates. If there is a aftermarket tune the tune will sometimes show up and GM will void the warranty. I have seen this on Duramax trucks only. Never on a gas motor, yet. But, I would be careful.
The Tech 2 showed 505ftlbs when I had my blower and I dynoed 509rwtq. I don't know if it is very accuate. However, on my truck it seemed very accuate.

 

Hmmm....
I dont know how my service consultant knew, but when my Hypertech was stuck on my PCM, he told me I had raised the shift points and the rev limiter along with advanving timing and stuff. He was pretty cool about it, and did mention to be careful, because it could fry my PMC. I just figured the computer immediatly picked it up??