Dudes and dudettes, I have a problem I really need to get fixed. I have an idea but need some help. I have a 2001 duramax. It runs great but when I want to pass or pick up speed I have power until the service light comes on and cuts the power. The truck will only rev to 2000rpm and run no faster than 65 or 70mph. When I turn it off and it sits for 30mins or more the light is off and it is fine until I want to push it hard. I think it is the EGR valve or the tank fuel pressure sensor. Whatchyall thank?