[Guest]

2002 XL Denali hesatatesafter being shut down for 1/2 hour then start driving & it is terrible for awhile

 

[Guest]

there could be a bad wrist pin, a thrown rod? yu could of smoked your motor

 

[Guest]

Maybe a valve is or two are not functioning properly, or you're using cheap/watered down gas.

 

[Guest]

Did we go 4 wheeling and beat on it a little to much this weekend?

Your timing could be off.

But sounds like a major tune up could also be a easy fix.
Pull some plugs and see what you got.

 

[Guest]

Engine shot?

How many miles?