P0304 cyl 4 misfire & P0303 3 cyl misfire?

2000 JEEP GRAND CHEROKEE
254 MILES • 4.0L • 6 CYL • 2WD • AUTOMATIC
Avatar
NJJETZGIRL
  • MEMBER
  • 1 POST
Hello, As of this past Sunday, my car has been running weird, not holding it's idle, constantly conking out at lights, engine light on ect... I recently had my car diagnosed and it showed I had a couple cylinder misfires, so I bought platinum spark plugs, and a new coil. Had them installed and still my car is not holding it's idle, conking out, and I am back to square one. I went for another diagnostic and it reads..... P0300 Random, multi misfire detected...... P0304 cyl 4 misfire & P0303 3 cyl misfire, now I already replaced the coil and plugs and engine light is off, so what could it be & what do I need to do now? I have a mobile mechanic coming later today but I would like some knowledge of my own.
Feb 26, 2015 at 5:26 AM
Advertisement
Avatar
HMAC300
  • CERTIFIED EXPERT
  • 48,601 POSTS
I have seen the MAP sensor cause this problem because the sensor will get weak and lean down the system. But we should do a compression test to make sure the engine is in good shape here is a guide to help.

https://www.2carpros.com/articles/how-to-test-engine-compression

If the compression is good here is the location of the map sensor so you can change it out, I would service the throttle body as well.

https://www.2carpros.com/articles/throttle-actuator-service


Check out the images (below). Please let us know what happens.
Feb 26, 2015 at 5:36 AM