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Old 08-20-2014, 04:15 PM   #1
Nas.a7x's Avatar
Join Date: Aug 2011
Posts: 1,149
bogging down and backfiring

95 2.5
OK so while going down the road at 55 in 5th gear my jeep started bogging way down and backfiring I had to down shift to 3rd and give it all the gas I could to keep it from dying. After about a minute it started running fine again. I ran the codes and the only thing that came up was code 21 for the o2 sensor but it came up twice. Is that going to be my problem? There's also no cat on it.

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Old 08-20-2014, 05:16 PM   #2
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Location: Ridgway, Pa.
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That would be the first thing I would replace.

It is probably due to the "no cat". Those computer controlled motors need stuff like that on them, for 1 thing it creates back pressure in the exhaust system which allows the rest of the system to work like it should. It might run great for a few weeks or even a few months, but somewhere down the road, it will require service because of the parts that were taken off of it. I personally am not a fan of a "cat", but if it makes the motor run correctly? Taking off the cat, and changing out the muffler to a glass pack or similar style like a flow master, just adds problems.

'87 YJ, 4.2L built and bored, 8.5" of lift, 8.8 rear, AX15/NP 231, Tom Woods drive shafts, Flat fenders, 12,000LB winch, Custom bumpers, Rattle can paint job. Never completed...
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Old 08-20-2014, 05:42 PM   #3
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Ya I plan on putting a cat on it sometime in the future. I already replaced to o2 sensor and it runs better, the check engine light hasn't come back on, it idles better also it would idle down to about 300 rpms before. I had to drive to town to get the sensor, about 14 mile round trip and it didn't do it then. I was sure it would at least help, but why would the code come up twice?
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Old 08-20-2014, 05:43 PM   #4
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Ya no glass pack I'm just running a stock muffler on it
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