2000 silverado wont go uphill easy

[1nasty86]

Fathers truck will idle fine and drives good untill the truck has to go uphill and seems to strugle and downshift instead of staying in gear and rpm'ing more into gear even on a small hill.... ive replaced fuel pressure regulator, plug wires, plugs, fuel filter and fuel pump.... could the egr, tps or maf be causing this? he has a 2001 silverado and it down not have this issue so its truck related

[efritz]

This would be best diagnosed with a scantool with live data stream capabilities as you have touched on all the "traditional" points already.

[dcheeseman]

How many miles? Could be a bad/clogged catalytic converter.....a clogged one will do this and truck will seem under powered.

 

Daniel

[1nasty86]

17k miles.... it was my grandfather's truck and never got driven

[GLSierra13]

2000 with 17k miles? How was it stored/parked? Mice have been known to crawl up a tailpipe and build a nest in the muffler.