will 2.9 to 4.0 conversion clog cat?

[wooky1971]

1991 Ranger/4.0/automatic/4x4

Hello everyone. I bought a truck that someone converted froma 2.9 to a 4.0. I know that when most people swap out the motor they never consider the cat. My question is will the extra emmisions end up clogging the cat over time.

Next let me first state that I dont care what it sounds like and I dont care if I gain more horsepower. My concerns are mpg, no loss of power, and no codes. If I hollow out the cat how will it affect my mpg and computer.

Yes. I know that running without a cat causes more pollution. The reality is that everyone should be driving electric cars but some of us have to drive a 22 year old vehicle and if we cant afford $150 for a new cat then we have to make do with what we can.

 

[doorgunner]

Can't advise you to hollow out the cat....that'll probably cause codes and will use more gas since it tricks the computer.....

I got a decent cat for $80 from autozone & installed it myself with some exhaust pipe adapters when I went to a bigger engine (didn't want a 20 year old cat causing flow /mpg problems)

 

[Sunk]

If your cat is clogged, it's not due to the 4.0 swap.

 

[alwaysFlOoReD]

As long as the motor is tuned properly and the cat is working properly there should be no issues with the swap.

Richard