Jeep Wrangler Forum - Reply to Topic
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum > p0303 code

Join Wrangler Forum Today

Thread: p0303 code Reply to Thread
Post Icons
You may choose an icon for your message from the following list:

Register Now

In order to be able to post messages on the Jeep Wrangler Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Additional Options
Miscellaneous Options

Topic Review (Newest First)
05-29-2013 01:23 PM
tbensor Thanks. I will pull again and check.
05-19-2013 10:17 PM
flflash If swapping the two plugs fixed it you may have a carbon track on the plug and inside of the plug boot, now that you've swapped them the two tracks no longer line up and cause the coil to short to ground.
If you noticed a line down the plugs ceramic you need to replace both the boot and plug or it will return..
05-19-2013 09:45 PM
tbensor I expected more replies but thanks GDAWG. I swapped 3 and 4 cylinder plugs and no issues. Mayne trash in the injector? I just seafoamed the tank. I will checkout the tsb for sure.
05-19-2013 05:56 PM
Gdawg Had this code on 2004 TJ. Check out Jeep service bulletin 18-031-03. Rough idle after hot soak. Install fuel injector insulator sleeve part # 56028371AA. Try to stay away from fuel with 10% ethanol (I use BP, my TJ seems to like it best)
05-18-2013 11:42 PM
p0303 code

I bought my 03 wrangler over a year ago with 137K on it. I now have 140K on it and this week I had my first issue. Drove it around town and stopped at the store. Fired it up and it stumbled badly. Threw a code P0303. I know this is a misfire on cylinder 3. I assume cylinder 3 is third from the front. I pulled the coil pack rail and noticed that the boot on the third from the from was discolored (maybe from heat?). I swapped 3 and 4 spark plugs(They looked fine) and it seems to idle fine. Haven't driven it yet to get it hot. I do not know when the plugs were changed. What recomendations do you have. Start with plugs or change both the plugs and the rail? Also how do I reset the code?

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

All times are GMT -5. The time now is 01:07 AM.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, and Grand Cherokee are copyrighted and trademarked to Chrysler Motors LLC. is not in any way associated with the Chrysler Motors LLC