To cat or not to cat, that is the question.

[JamminG4Jim]

The Cat converter on my '91 F-250 was removed by the previous owner. They just mounted a muffler in it's place and left the fresh air tubes dangling above it.

Should I replace the CC? Some say "just leave it off" and others say "It makes a difference on the way the truck runs". The drivers side o2 sensor trips the CEL after it warms up. Could this be related?

We don't have vehicle inspections anymore, so going without it IS an option.

I just want to know your thoughts and opinions on this.

Thanks,
Jim

 

[justin's_94]

If I were you I would just leave it off, I have an 1988 Bronco w/ 351W with no cats and I love the way it sounds. Your 02 sensor use to be in the cat convertor so you could get a new one and relocate it in the downpipe or muffler. It will stop your CEL from tripping all the time. It won't hurt the engine if you leave them off so it is your choice. I don't have any fancy computer stuff so I was fine. (your truck will sound better with those cats off to) Cutting off your cat convertors is also a good way to piss off the neighbors, that is why I did it at least.

 

[JamminG4Jim]

Hi Justin
That's the way i'm leaning also! My problem is that most of the bigger Muffler shop chains won't TOUCH my truck because the Cat Converter is missing! I'm going to have to find a shop that will custom form a dual exhaust for me. NOT a easy task!

I can't believe what the previous owners mechanic did. He WELDED the muffler to the joint where the two pipes from the exhaust manifolds meet. What a A-hole. That's where the cat would BOLT up to. Just this past weekend it started making noises like the muffler's leaking (or the weld is coming loose)...One more thing to fix. I don't mind,tho. It gives me the excuse I need to redo the exhaust the way I want it!!

Thanks for your opinions!
Jim