Have a 97 3500 and recently the truck after it gets warm looses power, the same hill I was going up in 4th I now have to go up in third. the boost will no longer stay above 20, and the engine sounds and feels like its missing, egts go up. Pulling 14k trailer. I am not sure where to start. I don't think it could be the intercooler since when cold its fine, possibly injectors?, turbo?. Not sure where to start.

 

It sounds like it might be ip related. Does the throttle get stiff when it acts up or stall?

 

Start simple, change your fuel filter, make sure the shutdown solenoid is all the way up when you experience power loss.

 

^Do what he said, also don't forget to clean the fuel strainer, as seen here- http://dodgeram.org/tech/dsl/filter/pre-filt_clean.htm

And if that doesn't help check the fuel pressure,it could be the overflow valve.
http://dodgeram.org/tech/dsl/trouble...p.htm#Overflow