USAIRPOWER

Not alot of power (above 35) it will burn rubber at slow speeds.

kgintner1

Yes it has a pressure valve on the passenger side fuel rail

udderbrudder

Is your SES light on? Codes may give you some direction in diagnostics. Even without a light on I'd scan it. Pay attention to long term fuel trim numbers if you can access this info. And as mentioned checking fuel press is a good starting point.

USAIRPOWER

It is giving p0420 codes which is expected from the lack of cats at the moment. Ill get more details for you guys when I go look at it again. Im just wondering what would be the worst case scenario for this issue. It may be some air/fuel problem, but the motor runs great at low speeds.

kgintner1

Compression test maybe?

garbill2003

I agree if the seller doesn't have a problem with it. and your topend power loss is almost for sure your exhaust. I worked on my buddies truck and it did the same thing .

2003XLT

Just tell him 3 grand and he won't hear from you again give him cash and use the forum to your advantage if it ends up not being the exhaust