Cherokee33

If anyone could help with this I would really appreciate it. My son's 98 Cherokee 4.0 recently had a freak happening. The O2 sensor wiring rear of the convertor contacted the driveline and damaged the sheathing of 2 of the wires. Of course the CEL came on so I replaced the downstream sensor. Codes were cleared, but shortly after they were cleared the CEL came on again and the engine began running rough a few minutes after cold start-up. This time the code was for the front O2 sensor heater circuit so I replaced it and the code cleared once again. Now after every start-up (approx. 3-5 minutes) the engine will sart idling rough and throw the same code (Upstream Sensor Heater Circuit). Most of the time it will clear itself up within a few minutes and sometimes it takes a bump of the throttle to clear it up. It is now beginning to sputter intermittently while driving. I've had a mechanic hook it up to a computer and run a complete check on it including the check of wire harnesses for resistance. I have spent hours reading on 2 different Jeep forums and haven't came with a solution yet. Since replacing the sensors, I have read that Bosch O2 sensors were not very compatible with Jeep's ECM. Is it possible that this could be the problem? Is it possible that the wires grounding out on the driveline could have damaged the ECM? If anyone has had a similar problem or could assist me with getting this straighted out it would be greatly appreciated. Thanks, Cherokee33

dudels99

had the same thing happen, wires rubbed the driveline and shorted the system. I replaced both o2 sensers still had problems, come to find out there is fuses for the o2 sensors, found one blown fuse, changed it and all prolems went away. the fuse is unmarked, located in the fuse block under the hood next to batt.

Cherokee33

YOU ARE THE MAN!!!

Thank you VERY MUCH for taking the time to reply. My son and I just went out and checked the unmarked fuses for a blown one. I had checked the fuses before but didn't bother with the unmarked fuses. Just as you experienced, we found a 15 amp fuse that was blown. We took a trip to Auto Zone, purchased a couple blue 15 amp fuses for $3, and replaced the blown fuse. We started the Cherokee up and made the trip home with no rough idle after start-up and a smooth trip home!!! Again, thank you very much for taking time to reply. I have posted this on 2 Jeep forums and noone has replied. You had the only reply and the problem was solved. This has saved us much headache and money because my next step was the dealership and you know how that goes. Please check your PM/E-Mail and reply.

dudels99

can we make this a sticky or something of the sort, I have seen this post a couple of times under trouble codes (po132) , (po135) ,(po138)

909daddy

I LOVE YOU, I LOVE YOU!!!!!!!!!!!!!!!!!!!!!!!!!!! i just spent 3 days and $200 in the shop, he didnt know what was wrong!!!!!!!!!!!!! his computer said all was good but it ran rough when i picked it up. got home... looked at fuse.... it was bad....... changed it out.. started it up.. taped gas pedal... engine smoothed out!!!!!!!!!!!!!!!!! YOU ARE THE MAN!!!!!!!!!!!!! Thanks for saving me $$$$!!!!!!!!!!!!!!!!!!!!!!!!!!

p.s. i called the shop and told the mechanic to join "CherokeeForum.com"... he laughed.

buckshot500

Wow!! I just went outside with a flashlight. I found one of the smaller Blue 15 amp fuses (back row 2nd from passenger side) that was blown. Been drinking, so I'm gonna ride my bicycle around to Advance.

Cool beans, thanks!

buckshot500

Ended up going today for the fuses. Popped it in & pulled a battery cable to reset the computer.

No C/E light, & no sputtering. Time will tell, but I think it's finally fixed.

This has been driving me nuts for a few months now, thanks dudels99 and Cherokee33. Y'all have made my day!


Great Tech!!!

.50Gunner

Yeah, been having a similar problem with my '97 Cherokee. Shooting me a trouble code of P0132. I'll start popping fuses tomorrow and see what I come up with. Its nice to think that the CEL problem will be solved as easily as that.

tablerockfshr

This is Awesome I have been dealing with the same thing except my wiring harness was pulled apart by weeds and after I plugged it back in it kept throwing codes, I did a lot of things to cure it but no luck till I read on here about the blue 15 amp fuse. I haven't replaced it yet but it was blown so I'm releaved and heading to the parts store for a new fuse,
Thanks for the info !!!!!

move over

Thanks you sloved my problem didn't know what to do already replaced two 02 sensors looked at the fuse it was blown replaced it CEL when off.Thanks Again

martinbuilt

This Forum is Awesome, Been working on a Friends Jeep replaced the rear O2 sensor because the drive shaft got a hold of the wiring and then got codes P0135, P0141 read this Thread and checked the fuse it was blown replaced it and all is well.
Thanks so much.
Martin

RockScout

I had the exact same problem, (drive shaft ripped out O2 sensor wires, and jeep slowly developed a stuttering problem, new sensor didn't fix the O2 sensor short (reported as both sensors shorted) because it turns out an unnamed 15A fuse is blown);

But in my case I'm also getting error codes for TPS sensor low voltage and transmition control system malfunction and the jeep still has its stuttering problem despite having a new fuse.

Is this a crazy coincidence or do you thing these problems could be related?

nickxj94

Turbine input Sensor on that trans, replace the tps then reset your pcm and see what happens

RockScout

Thanks Nick. Got her running good now. I guess it's just coincidence that my TPS crapped out at the same time I was going through the O2 sensor fiasco.

nickxj94

Been there lol