I was crawling around under my truck today just checking things out when I saw something strange. The pipe going into the cat is 3", coming out of the cat it looks like 4". The previous owner put a 3" cat back exhaust with a flowmaster muffler. The pipe out of the converter is crimped and welded onto the 3" pipe to the muffler. Is this creating a restriction? Were the factory pipes 4" behind the converter?

Thanx

John F

 

The factory exhaust was 3 inches. I would go ahead and ditch the cat and make it a 4 inch exhaust if you was worried about restriction.

 

Thanx

That's what I'm thinking about doing....when I get some more mad money.

 

mine is a 3 inch to the cat and then 4 after that.that is the factory set up.I junked it ,now 4 to 4.5 stackes(got stainless steel for free $600 worth,out of spec.shood be 4inch but 4.5)