Dillon98

I’m new to the forums. I have a 2000xj that’s been idling at like 300-400 rpm and running rough after warming up. The Rpms also don’t stay high after I’ve just started the engine when it’s cold and instead just drop right to 600-700 rpms. I scanned it and the codes were cylinder 1 misfire and bank 1 sensor 1 o2 sensor heater circuit. I changed the o2 sensor and then it gave me the bank 1 sensor 1 high voltage code and still the cylinder 1 misfire. Maybe the Jeep didn’t like the o2 sensor I got. I’ve changed the injectors, spark plugs, coils, TPS, IAC and cleaned out the throttle body recently so I’m ruling those out for the cause of the low idle. Could it actually be the o2 sensor causing it to idle so low and rough? Could use some advice

bluejeep2001

Disconnect any of your o2 sensors puts the system into pre programmed mode. If it fixes it then one of your front o2 sensors is bad...if not then probably not an o2 sensor problem