Error code P0421 - Jeep Wrangler Forum
Jeep Wrangler Forum

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

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 09-19-2010, 10:29 PM   #1
Jeeper
 
2006LJRubicon's Avatar
 
Join Date: Aug 2010
Location: Northern Kentucky
Posts: 41
Error code P0421

I have error code P0421 triggering my check engine light. Can anyone let me know what this means and what I need to do to fix it

2006LJRubicon is offline   Quote Quick Reply
Old 09-20-2010, 03:06 AM   #2
Jeeper

WF Supporting Member
 
Jp90Talon's Avatar
 
Join Date: Dec 2008
Location: CT
Posts: 3,137
P0421 OBD-II Trouble Code
Technical DescriptionWarm Up Catalyst Efficiency Below Threshold (Bank 1)

What does that mean?Basically this means that the oxygen sensor downstream of the catalytic converter on bank 1 is detecting that the converter is not working as efficiently as it should be (according to specs). It is part of the vehicle emissions system.


SymptomsYou will likely not notice any drivability problems, although there may be symptoms. The code may be more likely to occur after the engine has had numerous cold starts in the past 1-2 days.

CausesA code P0421 may mean that one or more of the following has happened:

*The catalytic converter is no longer functioning properly
*An oxygen sensor is not reading (functioning) properly
*A sparkplug is fouled up

My $ is on one of the last 2 (or so I would hope)

__________________
Jp90Talon is offline   Quote Quick Reply
Old 09-20-2010, 07:35 AM   #3
Jeeper
 
exboomer's Avatar
 
Join Date: Nov 2009
Location: Sacramento
Posts: 95
Reset the light and see if the code returns, if so the vehicle will need to be tested further. You might need a new cat conv??
exboomer is offline   Quote Quick Reply
Old 09-20-2010, 07:52 AM   #4
Jeeper
 
exboomer's Avatar
 
Join Date: Nov 2009
Location: Sacramento
Posts: 95
How many miles on the Jeep? Maybe it would be covered under the 8/80 emissions warranty?
exboomer is offline   Quote Quick Reply
Old 09-20-2010, 08:48 AM   #5
Jeeper
 
2006LJRubicon's Avatar
 
Join Date: Aug 2010
Location: Northern Kentucky
Posts: 41
it is a 2006 Unlimited Rubicon with 65,000 miles on it. I am not the original owner. ( I have had it for less than 6 months)

I have reset the code and within 200 miles it tripped again
2006LJRubicon is offline   Quote Quick Reply
Reply

Quick Reply
Message:
Options

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:
If you do not want to register, fill this field only and the name will be used as user name for your post.
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

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.



Thread Tools

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
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
P0421 Warm Up Catalyst Efficiency Below Threshold Bank 1 firefighter8816 TJ General Discussion Forum 3 06-25-2009 10:05 AM



» Featured Product

All times are GMT -5. The time now is 11:30 PM.



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