Is there any way you can tell if a truck has had a programmer run on it, or if it has been modded in any way? I don't know a whole lot about the Duramax, and am looking at buying an 06 LLY.

Thanks

I would think that the dealer with a Tech 2 could tell, other than that look on the passengers side exhaust manifold and see if it was drilled for an EGT probe.;)

I'd take a good look and a sniff at the trans fluid. If the tranny isn't fried, it probably hasn't been modded too heavily.

Tech II can only tell you the number of key on cycles on the pcm which if they are low, either a tune has been flashed or a code has been reset with a scan tool.