1997 Jeep automatic with 4.0 engine. In the mornings it seems to be fine on the way to work. On my lunch and after work when it’s up to temp it will buck, pop through exhaust/intake, backfire, stall out, lose power but never shut off and this is exacerbated by going uphill. Had a brand new upstream NTK o2 sensor installed early June. It does not have a cat. Possible it could be a failing crankshaft position sensor? Reason I ask is because it seems like it’s taking longer and longer for it to start in the mornings. I know Mopar sensors are recommended. Is there a part number for that and are they still available for purchase or would an NTK sensor suffice?
Bucking / popping / stalling when warm
- Thread starter JeepTJ02
- Start date
The P0132 code indicates that the engine control module (ECM) is reading a high voltage signal from the upstream O2 sensor, which suggests that it could be sensing a rich condition or there may be an issue with the O2 sensor itself. Since you mentioned that you recently replaced the sensor, it could be worth double-checking the installation and the connections to ensure they're secure and not corroded.
More often than not the issue ends up being damaged wiring. This can be very tricky to track down unfortunately since often times you end up having to go through the entire wiring harness.
The crankshaft position sensor could also indeed be a culprit, especially since you're experiencing longer cranking times in the mornings and issues when the engine is warm. A failing crankshaft position sensor can lead to erratic engine behavior, and it's not uncommon for them to fail under heat. I believe in the FSM there is a test procedure for the CPS in which you can use your multimeter to test it and confirm whether it's bad or not.
Mopar parts tend to be more reliable than aftermarket, so if you decide to replace the sensor, I would recommend going with the Mopar crankshaft position sensor if you can find one.
In the meantime, you might want to check for any vacuum leaks or issues with the fuel system as well, as they can cause similar symptoms.
I’m curious if the o2 sensor is the culprit. I just replaced it June 5th with A NTK 23179. I’ve never had bad luck out of NTK sensors before. I’m having a VERY hard time finding a Mopar crankshaft position sensor. Does anyone have experience with an NKT CPS?
My bet is either a short in the wiring or the CPS. I wouldn't hesitate to buy a NTK CPS. They make good stuff.
I replaced the o2 sensor with another NTK unit that I got on warranty this morning. Still doing the same thing. I’m leaning more towards crank sensor now.
Did you find your issue having same issue on my 2000 tj just replaced both O2 sensors with new NTK sensors still have a P0132 code with bucking backfiring and wanting to stall out? Was the CPS your culprit?
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