Dual Emission MIL codes - 0420 and 0137 - JeepForum.com
LinkBack Thread Tools
post #1 of 3 Old 07-06-2013, 04:15 PM Thread Starter
Registered User
2004 KJ Liberty 
Join Date: Feb 2011
Location: Wethersfield
Posts: 10
Dual Emission MIL codes - 0420 and 0137

My wife's 2003 Lib's MIL light has been intermittent over the last week. I hooked it up and stored are the P0420 and P0137 codes. The dealer gave her a laundry list of items that would 'require' replacement to clear the codes but I was wondering what the more likely culprit would be from a more knowledgeable group.
Thanks in advance.

ETA: Stock. 115k miles. Normal fuel consumption. Local daily driver. Smooth idle. No smoke at startup or while driving.

Last edited by mu2bdriver; 07-06-2013 at 04:29 PM. Reason: Content
mu2bdriver is offline  
Sponsored Links
post #2 of 3 Old 07-06-2013, 05:47 PM
Registered User
2005 KJ Liberty 
Join Date: Jul 2011
Location: Castle Pines
Posts: 3,296
P0420, Bank 1 kitty cat is dirty and isn't working correctly or it thinks at least. Usually means B1 cat needs replacing, but I always verify before condemning. P0137, could be a symptom of a problem upstream with the engine running lean, or could be a faulty sensor. Hint, if you go to replace the O2 sensor, which I would consider before the Cat, do not, let me repeat DO NOT buy a bosch sensor. Use the OE, or an NTK(ngk) sensor.
streetglideok is offline  
post #3 of 3 Old 07-08-2013, 10:44 AM Thread Starter
Registered User
2004 KJ Liberty 
Join Date: Feb 2011
Location: Wethersfield
Posts: 10
mu2bdriver is offline  

Quick Reply

Register Now

In order to be able to post messages on the JeepForum.com 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 e-mail 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.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page

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 On
Refbacks are On

For the best viewing experience please update your browser to Google Chrome