Exhaust Question

the short and simple is i need a new exhaust pipe basically from the header back, the stock pipe is smaller than 2.5" which is what i was going to go to.... will 2.5" pipe create any backpressure problems?

(and yeah i know i need a new muffler and cat too)

i would just go w/ 2.25" pipe and a super 40 muffler. unless you gota pass inspections youll be fine w/ just a muffler. hell i just took my 40 series out and put in a glasspac because I wasn't getting the sound i want. I have full 2.25" pipe back from header.

Stock 4.0L exhaust is 2-1/4". I ran a 2-1/2" turbo muffler and cat back for a few years. Sounded mean, but when it finally rusted out I replaced it with a stock 2-1/4" system and was surprised by how much low-end torque I regained.

I've just done the same thing Eagle did. I ran a high flow cat and 2 1/2" custom exhaust for the past three years or so and just went back to a stock set up and am satisfied with the change. He's right about the decibel level too. Sometimes the dog doesn't even hear me coming up the driveway now.