Tuners leave signatures???

[Dave338]

I've been wondering if these tune-up artists that some of you have tune your rigs leave any kind of I.D. visable on the ECM?
I bought a used 03 Z71, 5.3/auto trans, ex-cab that I fell in love with on the first test drive. This thing ran like a raped-ape!!! Got 17mpg around town, would chirp the 265/75R/16's going into second gear and pulled 8000 pounds worth of horse trailer like it was fun. This truck had stock exhaust, and the only thing I found that had been done was that K&N air intake.
Was it tuned??????? Of course by looking at the ECM, I couldn't tell. I've driven several other trucks since I got that one and none compare.
I finally broke down and traded it this week. I had to go bigger because of the towing. Got an 04 2500 with the 6.0, it doesn't run anything like that 5.3. Missin it already.

[jeverett]

It sure sounds like it was tuned. But sometimes there are a few trucks that just get tuned "special" from the factory. Theres a 2000 GMC here that runs like hell and gets 25+ mpg all day long from the factory. I guess it was just tuned better than the rest that day.

[fuzzypuppy]

I'm getting all the gear and programing together to start chip tunning myself, I got the idea from, thirdgen.org.
I know they can do some pretty killer stuff with just reworking the chip on camaro's, firebirds and vett's, I plan on keeping my deal a GM thing only, no imports.
You can change shift points, timing curve, injector pulse width, speed govener, etc.
I can't wait to see what I will be able to make my truck do with all this

[Blue Bowtie]

I use either the PROM/Mask I.D. byte to encode the month/year of the programs I've written to a PROM, plus the BCC label on the DIP or case itself. Some people probably just burn a program and forget it, but it's nice to be able to read a binary and know that it isn't a factory or stock tune.

[Rmbodie]

On the subject of programmers . Yesterday I read on jetchip.com that their plug up programmer can only be used on one vehicle . It copies the VIN into memory and will not except another . Rob