Check engine light turned on for code P0303?

Tiny
MATT FRASER
  • MEMBER
  • 2018 JEEP GRAND CHEROKEE
  • 3.6L
  • 6 CYL
  • 4WD
  • AUTOMATIC
  • 86,000 MILES
I got a check engine light code for P0303. Brought it to mechanic and he said it could be spark plugs or ignition coils. So, to be safe I replaced all of the spark plugs and ignition coils. Fast forward a week later I get the same code again. Not sure what to do now. Maybe could be a sensor on the intake?
Wednesday, October 11th, 2023 AT 5:00 AM

1 Reply

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 49,970 POSTS
It could be the fuel injector has gone out, but we should remove the spark plug on #3 to see what it looks like, if it has very little color on it the fuel injector could be bad. Here is a guide on misfires that can be helpful, and I have included how to change the fuel injector out.

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

These engines had problems with the valve train, when the engine is running can you hear ticking coming from the #3 cylinder? Check out the images (below). Please let us know what you find.
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Wednesday, October 11th, 2023 AT 8:21 AM

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