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Discussion Starter · #1 ·
So I am a proud new owner of an old wrangler. 1997 Sport to be exact. My wife wont stop yelling at me to get off of this forum, but all of the information is amazing.
Anyway, I have searched a ton of topics and I am just looking for where I should start looking for my problem.
Jeep starts up and runs without any issues at all. After about a minute of idling the jeep begins to hesitate and sound as if it is going to stall. This continues for about a minute and then the jeep runs beautifully.
If I shut down the jeep for a few minutes it will start right up and run fine. If it sits for about a half hour or longer the problem is there again.
From my forum searches it seemed to me like it might be the o2 sensor, so I ordered one and it will be here tomorrow night.
Before I go installing it maybe you all have some insight, troubleshooting steps I can take.
Thank you all and I look forward to your expertise.
 

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Sounds like the upstream o2 sensor, and that's how mine acted when it went bad. Would run fine when 1st started (open loop), then when the engine warmed up it went to closed loop, and ran like crap until the sensor heated up, then it ran fine.
You could try disconnecting the Upstream o2 sensor and see how it runs. Also go thru and clean the TB & IAC.
Remember to only replace them with NGK/NTK sensors.
 

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Discussion Starter · #3 ·
Okay great. So I ordered a Bosch o2 sensor. No good? Should I return it or go with it this time and NGK if it goes again?
Also, is this a problem with the sensor itself or is something causing the sensor to do this?
 

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I bought the Bosch sensor first, and didn't help anything. If it was me I'd return it and get the NGK sensor. I don't think it's anything causing the sensor to fail, they have a heater circuit built into the sensor and that's what failed on mine. That's why once the exhaust warms up the sensor it operates fine. But until it does it messes with the fuel/air mixture causing bad mpg, rough idle, etc...
 

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Discussion Starter · #7 ·
So my new o2 sensor has not arrived yet but today I disconnected the o2 sensor and the jeep ran perfectly. Does this nail down the problem of the o2 sensor or will the problem resume even after I plug in the new o2 sensor?
Also, is it okay to run with the o2 sensor unplugged until I get the new one installed?
Thanks for your help!
 

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I'd shy away from running with the sensor unplugged - but then again, if it's jacked up your computer can't make the correct air/fuel ratio calculations anyway. Just my $.02 but I personally just don't like the thought of running without necessary equipment.
 

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Discussion Starter · #9 ·
It is lifted 2". Is there something I should be doing if it hasnt been done already to adjust the computer to compensate for the lift?
 

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So my new o2 sensor has not arrived yet but today I disconnected the o2 sensor and the jeep ran perfectly. Does this nail down the problem of the o2 sensor or will the problem resume even after I plug in the new o2 sensor?
Also, is it okay to run with the o2 sensor unplugged until I get the new one installed?
Thanks for your help!
Yeah that would narrow it down to the o2 sensor
 

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It is lifted 2". Is there something I should be doing if it hasnt been done already to adjust the computer to compensate for the lift?
Haha no sir. Your lift has nothing to do with your computer. Don't worry.
 
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