I have a 96 dodge 2500 that is bone stock except for a 4 in exhaust. the problem I am having is that when I put it in drive or reverse it starts loping like it has a cam in it. It does not do this when is park or neutral. It seems to be worse when the weather is hot. Any suggestions?
I looked on here before posting but all the loping issues are when they are parked.

 

Mine used to do that when I turned the AC on in drive or reverse. I turned up the idle to 750-800 rpm's in gear with the AC and it went away. It sounded sweet but not enough rpm's! Lol

 

agreed^^ mine loped when at a stop in drive. turned the idle up and now its fine.

 

Thanks for the help. Now I will see how to turn up the idle on this thing.