So I need a new exhaust on the truck. Both tubes that go into the cat have rotted out. I assume these are from the air pump. That's the cheapest way to do an exhaust. I use the truck for plowing my own driveway and occasionally dump run. Just want something quite. Can I eliminate air pump and plug ports in back of manifolds or should I just buy all new.

 

What engine and year, what are the state regulations, and do you plan on keeping it street legal?

If not, then remove the Smog pump. Get a shorter belt. Plug all associated vacuum lines. Plug the holes in the cats and heads. Other then that get it fixed.

I would recommend getting it fixed to work properly. You will not gain any power with its removal. Just makes the engine bay easier to work in.

I have mine plugged....on my 5.8L

 

It's a 1990 with a 7.5. In ct because it's 20 years old or more no emission tests are required. I just use it to plow driveway and occasionally dump run.