Troubles with 97 XJ
Newbie
Joined: Jun 2010
Posts: 9
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Model: Cherokee
same
new here but do check the forum...great help!
having the same type of issue - more the stubble and popping like 4x4 mentioned, only thing messing with me is that the check eng. light has not come on-could this still be an 02 issue for me? thanks!
having the same type of issue - more the stubble and popping like 4x4 mentioned, only thing messing with me is that the check eng. light has not come on-could this still be an 02 issue for me? thanks!
Member
Joined: Dec 2009
Posts: 109
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From: Tooele, Utah
Year: 1997
Model: Cherokee
Engine: 4.0
Yeah it could still be your o2. I had a check engine light but it was a totally unrelated issue. I replaced my map, tps, and cleaned my iac and those didn't fix anything. The o2 on my downpipe was just the next troubleshooting step in my opinion and I finally lucked out with that. I never realized the upstream o2 is as important as it is until I ran into this problem. I'm not an expert mechanic but I have some skills and rationality behind my thought process. lol This forum has helped me out alot since I've been on it. I get bored at work and just research anything and everything that could or would apply to my jeep either now or in the future.
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Newbie
Joined: Jun 2010
Posts: 27
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Model: Cherokee
Newbie
Joined: Jun 2010
Posts: 9
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Model: Cherokee
thanks 4x4! i think that is my next step...i also have no problem getting into it. I have done somethings up to this point-plugs wires cap rotor pulled the injectors fuel press. same here-looking for any info..
Member
Joined: May 2010
Posts: 193
Likes: 1
Model: Cherokee
You can replace the cat with a straight pipe if you want then get 2 spark plug non-foulers(that fit the o2 thread) stack the 2 cutting the hole in the first one(connected to o2) so the probe can stick through then screw it back to the bung. This will restrict the amount of exhaust getting to the sensor eliminating the chance for a code.
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Joined: Jun 2010
Posts: 27
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Model: Cherokee
Thanks, a buddy of mine also just told me about doing this......I have scene mixed reviews on if it works well or not and how well it works for a jeep? does anyone have any experience with doing this and can you tell me how well it worked?
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Newbie
Joined: Jun 2010
Posts: 27
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Model: Cherokee
what year jeeps do you have and are they obd2?
will this mod only work for the post cat o2 or will it also work on the down pipe?
I am assuming only post cat because the first o2 reads the mixtures coming directly from the engine where as the post cat o2 reads the "cleaner" mixture after passing through the cat.......and the point of moving the o2 up out away from the pipe partially with the non fowlers is to keep it directly out of the fume stream so it cannot make an accurate reading and throw a code because there is not cat.......right?
just trying to figure it out and weigh all the options so i can see what needs to be done.
will this mod only work for the post cat o2 or will it also work on the down pipe?
I am assuming only post cat because the first o2 reads the mixtures coming directly from the engine where as the post cat o2 reads the "cleaner" mixture after passing through the cat.......and the point of moving the o2 up out away from the pipe partially with the non fowlers is to keep it directly out of the fume stream so it cannot make an accurate reading and throw a code because there is not cat.......right?
just trying to figure it out and weigh all the options so i can see what needs to be done.
Seasoned Member
Joined: May 2009
Posts: 296
Likes: 1
From: Wy & OK
Year: 83 CJ7 & '96 XJ & '97 XJ
Model: Cherokee
Engine: 258ci, 4.0 & 4.0
Im not going to bother with taking the jeep to a "wanna be mechanic" behind the counter at autozone lol....I already know that it needs an O2 sensor so I know thats what is going to show up on a code reader.
also....installing an O2 sensor into a straight pipe without a cat would seem like it would be pointless.....because there a is a pre-cat and post-cat O2 sensor....one to read the levels directly after leaving the engine and one to read the levels after it has passed through the cat .....if there is no cat the rear O2 would sense that the levels are about the same as what was picked up at the front O2 sensor and it would richin/lean out the air/fuel ratio to compensate and would still make it run like crap.
if in fact it is an O2 sensor problem I am having, I will either need to get a new cat and a new O2 sensor (mine is busted) or I can eliminate the cat and replace it with a straight pipe.....and I can then get an O2 sensor simulator (if they make them for these jeeps) to trick the computer into thinking the O2 sensor is plugged in and making correct readings.
anyone else want to chime in on the subject?
also....installing an O2 sensor into a straight pipe without a cat would seem like it would be pointless.....because there a is a pre-cat and post-cat O2 sensor....one to read the levels directly after leaving the engine and one to read the levels after it has passed through the cat .....if there is no cat the rear O2 would sense that the levels are about the same as what was picked up at the front O2 sensor and it would richin/lean out the air/fuel ratio to compensate and would still make it run like crap.
if in fact it is an O2 sensor problem I am having, I will either need to get a new cat and a new O2 sensor (mine is busted) or I can eliminate the cat and replace it with a straight pipe.....and I can then get an O2 sensor simulator (if they make them for these jeeps) to trick the computer into thinking the O2 sensor is plugged in and making correct readings.
anyone else want to chime in on the subject?
Member
Joined: May 2010
Posts: 193
Likes: 1
Model: Cherokee
what year jeeps do you have and are they obd2?
will this mod only work for the post cat o2 or will it also work on the down pipe?
I am assuming only post cat because the first o2 reads the mixtures coming directly from the engine where as the post cat o2 reads the "cleaner" mixture after passing through the cat.......and the point of moving the o2 up out away from the pipe partially with the non fowlers is to keep it directly out of the fume stream so it cannot make an accurate reading and throw a code because there is not cat.......right?
just trying to figure it out and weigh all the options so i can see what needs to be done.
will this mod only work for the post cat o2 or will it also work on the down pipe?
I am assuming only post cat because the first o2 reads the mixtures coming directly from the engine where as the post cat o2 reads the "cleaner" mixture after passing through the cat.......and the point of moving the o2 up out away from the pipe partially with the non fowlers is to keep it directly out of the fume stream so it cannot make an accurate reading and throw a code because there is not cat.......right?
just trying to figure it out and weigh all the options so i can see what needs to be done.
I agree that it would be better to install a new cat, on some vehicles (like my 96) the O2 was mounted right on the cat not after it. The point I was trying to make is that what I did was simple, after I did it the PCM was happy and the Jeep runs great. MPG are real good and it runs pretty much like new. I'm just curious, what would be the benefit the simulator over the way I did it?
Last edited by Weou09; Jun 17, 2010 at 07:58 AM.
Thread Starter
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Joined: Jun 2010
Posts: 27
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Model: Cherokee
Thanks for all the input guys, I will most likely end up going straight pipe and see how it runs and if it still runs bad than I will weld in a bung and put an o2 in and if that does not do the trick than I will try using a non fowler and see if that does the trick.....when I get around to it i will update you guys, thanks
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