Code P0303, misfire?

Tiny
DJMEATMAN
  • MEMBER
  • 2010 JEEP WRANGLER
  • 3.8L
  • V6
  • 4WD
  • AUTOMATIC
  • 275,000 MILES
Got a P0303 code, so far, I have changed the coil, plugs, plug wires. Ran fine after sat for a day started up and threw the P0303 code again. What should my next project be injector maybe?
Monday, May 22nd, 2023 AT 11:28 AM

3 Replies

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,624 POSTS
Yep, the fuel injector would be next. Can I ask if the engine is making a slight ticking sound? If so, can you please shoot a quick video with your phone so I can hear the noise? that way I can tell for sure what's going on. You can upload it here with your response. You might have a valve train problem.

Here is how to change the fuel injector out and a guide on misfire problems:

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

and

https://www.2carpros.com/articles/symptoms-of-engine-misfires-a-step-by-step-guide

Check out the images (below). Let us know what happens and please upload pictures or videos of the problem so we can see what's going on.
Was this
answer
helpful?
Yes
No
Monday, May 22nd, 2023 AT 5:58 PM
Tiny
DJMEATMAN
  • MEMBER
  • 2 POSTS
Okay, thank you. No ticking, so my next project will be injectors, should I replace all 6 while I have it apart being it has 275,000 miles and I don't know if they are the original ones?
Was this
answer
helpful?
Yes
No
Tuesday, May 23rd, 2023 AT 10:10 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,624 POSTS
Yep, that would be the next step. Also, I have seen these engines have a lot of intake port carbon build up which can cause misfire issues. Have you done a compression test?

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

Please go over this guide and get back to us.
Was this
answer
helpful?
Yes
No
Thursday, May 25th, 2023 AT 9:36 AM

Please login or register to post a reply.

Sponsored links