2004 chevy 2500hd 6.6 duramax diesel. the truck runs and idles but nothing happens when i step on the pedal. its as if the truck wasn't running at all.

Moved to 1st Gen Duramax

there is a post on here about the pedel switch going bad. Sounds liek you have the same issue

That would be my guess. Change out the throttle position sensor and try that.

You can check out my post on the subject here:

http://www.dieselplace.com/forum/showthread.php?t=366925

I changed out the throttle position sensor. Very easy to do...we'll see if the problem recurs again.