Should I install catalytic converters and O2 sensors in my TJ?

PaulieB

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Guys, I have a question. I bought this used Jeep Wrangler 2004, 4.0 with manual tranny. The guy I bought it from said it had a new exhaust and it does however, they didnt put a catalytic converter and removed the oxy sensors. It seems to run pretty good but I would expect more. Is it worth the expense of installing these items ??

Thanks in advance all.
PaulieB
 
I wouldn't worry unless you have emissions testing or throwing a code as it will fail.

We do Cat delete quite frequently around here on our Jeeps and trucks and / or burn out the internals of the cat and modify the downstream 02 to full the ECU.
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It is against federal law to drive on any public road with a modified emission system whether or not your state requires emission testing.

At any point you can be checked and fined, or worse yet have your vehicle impounded.

Just saying
 
Not to be a whiny blue-stater, but catalytic converters do exist for a reason, to reduce carbon monoxide, nitrogen oxides, and hydrocarbons which is the reason smog in cities used to be a lot worse.
 
I wouldn't worry unless you have emissions testing or throwing a code as it will fail.

We do Cat delete quite frequently around here on our Jeeps and trucks and / or burn out the internals of the cat and modify the downstream 02 to full the ECU.View attachment 110410
How do I fool the ECU ??
 
I can't imagine you're really going to gain anything by deleting your cat in these trucks. In sports cars, you often times actually see a decrease in performance (on the lower end) with a higher flowing exhaust as the engine uses the back pressure to create negative pressures that drive the next "puff" of exhaust out. Not sure what the case is with the TJ, but lets say you get a 10% increase, aka a whole ~18whp, for the trouble of having to shoestring together some illegal and environmentally harmful solution.
 
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You will notice a decrease in power with no cat unless you have a highly modified drive train. Your back pressure will never be right either

I have a 98 trans am that has a gutted cat, a $1000k exhaust a reprogrammed ecu. The exhaust smells terrible this was all done prior to my ownership. I personally would not do it.

You need to reprogram the ecu to fool the computer...
 
I wouldn't worry unless you have emissions testing or throwing a code as it will fail.

We do Cat delete quite frequently around here on our Jeeps and trucks and / or burn out the internals of the cat and modify the downstream 02 to full the ECU.View attachment 110410
2cats are expensive to replace. Is it worthwhile to replca the downstream O2 sensors first?
 
2cats are expensive to replace. Is it worthwhile to replca the downstream O2 sensors first?

If you don't have cats at all as in the context of this thread, replacing O2 sensors isn't going to get rid of your codes.

If you do have cats, maybe.