Catalytic convertor removal

I have my rear cat and muffler replaced with a straight pipe. It's not stupidly loud compared to running open headers and it sounds great starting up in the morning.
 
ok my question here I am not wanting to get louder or faster, but my jeep has been running horrible all signs point to clogged cat 2001 tj looks like factory exhaust I plan to pull the exhaust to check the cats. I sadly don't have the 1000 to replace the whole system, if i have a clogged cat will it hurt my motor if I hollow it out and run it until I can replace them all? Please and Thank you!
 
Depending on how plugged they are you might just drop them and clean them out. You won't pass an emissions test but you will get back all the power. I did this 3 years ago, No issues but we don't have emissions testing either.

I think TJs have 3 cats but the big one under the seats is usually the problem.
 
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You'll have significant power loss with a clogged cat. Remove it, bang all that shit outta there with a BFH and a piece of pipe, then reinstall. It might be slightly louder but you'll barely notice after a while. I live in CA and I ran my XJ like this for about a year and a half. We have emission test every 2 years so when it came time for the test, I forked out the cash for a new cat.
 
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AidenC said:
what cat do you think it is causing trouble?
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not sure hoping for the secondary that is on the skid plate so I can cut the pipe there and check it clean it out if needed and reattach with a coupler without having to pull the primary cats. I know I am going to have to pull them eventually to replace they are almost 20 no they are 20 years old. I just don't have the excess cash at this point.
 
Jorge said:
bringing back this thread. cant you use o2 sensor bungs, weld them on to the tube and out the sensors back on?
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what would you do with the existing ones then? I don't think it would throw any code if you moved the sensor bungs to fit a spark plug non fouler on it. I wish there was a way to disable the afterflow O2 sensors.
 
I understand the first two are there to regulate fuel mixture but the ones behind the precats do nothing but just sit there and throw codes.
 
So I've been hearing a rattle when I'm idling and when I'm at about 1800 rpm. I think it's the cat but im not 100% I have stalled a few times and it does seem a little bit down on power. And it just put up a p0441 code
 
Charlesmjroberts said:
So I've been hearing a rattle when I'm idling and when I'm at about 1800 rpm. I think it's the cat but im not 100% I have stalled a few times and it does seem a little bit down on power. And it just put up a p0441 code
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Early TJs like your 97 did have a problem with their cats coming apart inside and rattling. My 97 did the same thing but it was still under warranty so the dealer replaced it with the updated catalytic converter. You can take a mallet and bang on it a bit to see if you hear it rattling inside to confirm if it's the source of the rattling.

The P0441 code indicates a leak in the evaporative system. That can also be caused by starting or running the engine while the gas cap is off.

Finally, that P0441 code says you used an external code reader. Your 97 can produce its own DTCs (diagnostic trouble codes) by turning the ignition switch on-off-on three times within five seconds and then leaving it in the On position. Give the diagnostic route time to work, 4-5 seconds is enough, and any stored codes will start displaying in your odometer. If you did it right you will at least see a '55' code which simply indicates there are no more DTC codes to follow.

Since the '97 produces two-digit codes instead of the P0123 type codes of newere TJs, here's how to decode them... https://www.allpar.com/threads/the-1980s-1990s-chrysler-computer-codes.229009/#post-1085223107
 
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Thank
Jerry Bransford said:
Early TJs like your 97 did have a problem with their cats coming apart inside and rattling. My 97 did the same thing but it was still under warranty so the dealer replaced it with the updated catalytic converter. You can take a mallet and bang on it a bit to see if you hear it rattling inside to confirm if it's the source of the rattling.

The P0441 code indicates a leak in the evaporative system. That can also be caused by starting or running the engine while the gas cap is off.

Finally, that P0441 code says you used an external code reader. Your 97 can produce its own DTCs (diagnostic trouble codes) by turning the ignition switch on-off-on three times within five seconds and then leaving it in the On position. Give the diagnostic route time to work, 4-5 seconds is enough, and any stored codes will start displaying in your odometer. If you did it right you will at least see a '55' code which simply indicates there are no more DTC codes to follow.

Since the '97 produces two-digit codes instead of the P0123 type codes of newere TJs, here's how to decode them... https://www.allpar.com/threads/the-1980s-1990s-chrysler-computer-codes.229009/#post-1085223107
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Thank you very much I didn't know that abt the early TJs ill look into it tonight
 
1995XJ&2006TJ/LJ said:
went back down to 15 mpg no matter how easy or hard I would drive it.
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That's the magic number. The magic number for my '87 XJ was 20-21mpg hiway burning straight 86 regular; ethanol busts it to 18-19 mpg. Once, I got 26mpg blowing through Kansas with a tail wind. They sold no ethanol there.
 
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