Ok,so I have changed the timing chain, new MAP sensor, cleaned the throttle body, new plugs and wires, Catalytic converter was checked by a shop its good, trani good. Fuel pump and filter were changed not long before I bought the truck, I think that is it, and yet I still have a dog on the freeway, it feels like a bad cat, but the shop says "no its good".
The muffler shop that inspected my cat said that I need to remove some extra muffler thats installed to reduce noise and replace the other normal muffler with a good truck muffler. Can a muffler impact the performance that much, its not like its a cat.
could there be something else I can change that will cost me less than a new muffler and would impact the performance in positive way?
thanks in advance
P

 

Is the truck running in limp mode? When you say "dog" I assume that it is not running well, as opposed to running normal, but underpowered for your intent.

 

if there are no codes coming up then it could be an exhaust issue... restrictive or clogged muffler, bent piping, etc... never a bad idea to bolt up a cat back exhaust with good sized piping and a flowmaster style muffler.

 

Siggie, It runs well but just not what I would expect from a v6, I have a van with a 3.3L and it has more poop than the 3.9L. And Z guy, sounds like my muffler guy could be right.
thanks gents

 

Had the muffler changed, significant difference. But still a little slow off the line and at top end, maybe its because it has towing transmission?
I dont know, anyone got other ideas.
thanks

 

Engine size dictates potential, not performance. The cam on the engines dictate your powerband, which on these trucks, is not highway oriented.

The cam is the culprit with the top end. As far as off the line, not sure. I do not know what a towing tranny is, but a v6 has the 42rh. It doesn't sound like you are looking to modify your drivetrain, so if it's not broken, then it is what it is.

 

Yup, I think it is what it is. I also failed to mention that my tires are a bit bigger than the usual, which may impact the torque
thanks all for your input.