Hello all first post here. Looking for help diagnosing a misfire issue. I start up the car it runs fine, after about 2 minutes it develops a random miss P0300. If I shut the car off and restart it runs fine afterwards till I shut down and let it sit for awhile. Then I go through it all again. I do have a o2 sensor heater code, and a bad oil pressure sensor (reads 99 on scanner). Putting it in tow/haul mode doesn't help. I'm thinking it's a sensor issue as I can restart and it goes away. I've replaced crank sensor and it still has the issue. Any ideas would be great. Thanks.

 

Hey There, the O2 sensor is an integral part of fuel control (lean/rich) i would get that replaced. Not sure about your oil sensor but if it stalls at idle, especially on drive and at idle, you need that replaced also. For the oil sensor seems you have replaced it before....check the electrical.

 

Surely you have already solved your problem by now, but maybe someone else will benefit from it. I had the same issue with two Chryslers, and it's most likely the O2 sensor. When it's cold, it gives incorrect readings, hence the need for the heater. Apart from a faulty heater, your sensor is probably fully functional, which is why the problem only reoccurs after a period of inactivity.