Loss Of Power When Towing

[stss95]

I have an 05 silverado and while towing my boat (about 3500lbs.) I get a loss of power on the highway, hit the gas and it won't go. couldn't get over 55mph at one point. engine doesn't rev it just stays flat... truck has 50k on it only mods area a cat back... any clues where to start looking first...???

 

Its a 5.3 auto with i beleive 3.42 gears and the gas mileage also went downhill 12.8mpg

[wavery]

I have an 05 silverado and while towing my boat (about 3500lbs.) I get a loss of power on the highway, hit the gas and it won't go. couldn't get over 55mph at one point. engine doesn't rev it just stays flat... truck has 50k on it only mods area a cat back... any clues where to start looking first...???

 

Its a 5.3 auto with i beleive 3.42 gears and the gas mileage also went downhill 12.8mpg

It could be any number of sensors. It could be the cat converter.

 

Don't mess around, get it checked out before one thing leads to another.

[HawkScot]

plugged converter or fuel filter..

[GMstrong]

fuel pressure.