I was driving our other 96 R1500 5.9 auto 4x4 yesterday and going up a hill with the cruise on it downshifted but started slowing down and losing power so i shut off the cruise and held the gas pedal down and nothing ? Has anyone ever had this happen and what fixed it ?

 

Drove the truck yesterday and when it downshifts going uphill it doesnt make power kinda like its in a limp mode ? Any ideas guys ?

 

Sounds like we should get Master Tech involved here.

 

Plenum fixed? Cat clogged? How old are the O2's? Last time it had a tuneup?

 

it might be the cat because i think i can hear it ratteling some ?

 

Get it tested.

 

You might be hearing detonation. Do you have responses to HeyYou's questions in post#4 above? Have you read the plenum sticky?

 

Gonna get a Y-pipe and cut out the cat and delete it when i get time ! Its not detonation because i know one from the other (Been a mechanic for 20 yrs) ! Just thought i would throw it out there before i spent long hrs tracking it down ?