Code p0420 help -
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back > Jeep Forum Site Help & Support > JeepForum Announcements > Code p0420 help

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineFS: Jeep Fog Light LED Bulbs! Several Brightness Options! RCV Axles at CCOR

View Poll Results: What is my problem code p0420
Oxygen sensor 1 100.00%
Defective catalytic converter due to # 2,3,4 0 0%
Engine misfire or large vacuum leak 0 0%
Engine oil leak into exhaust 0 0%
Multiple Choice Poll. Voters: 1. You may not vote on this poll

Unread 01-22-2014, 10:50 AM   #1
Registered User
Join Date: Jan 2014
Posts: 1
Code p0420 help

Hello my engine light came on I ha in plugged in and code p0420 came up. I have a 2005 jeep grand Cherokee lardo trail rated edition. Now my question is what causes this. My jeep is running fine I didn't notice any problems. While I was driving it the light came on and I checked the oil and had almost no oil. The oil light didn't come on to let me know and I just had an oil change last month. There is no oil leaking onto the ground so not sure what happened. It says it could be the oxygen sensor, catalytic defective due to #2 3 or 4, engine misfire or running condition, large vacuum leak, engine oil leakage into exhaust-valve guide piston rings. Can anyone help me don't want to fix something when it we'll could of needn't something else. Thank you for your time!!

poptart0722 is offline   Reply With Quote Quick reply to this message
Unread 01-22-2014, 03:31 PM   #2
Web Wheeler
AmbuGrl's Avatar
1998 XJ Cherokee 
Join Date: Oct 2009
Location: Virginia Beach, Va
Posts: 2,395
Wrong forum, try here
- HM1(SW/AW)Ret USN Dec 23,1992 to Dec 31, 2012

I drive an XJ, and all of my power windows work :)

2000 Pontiac WS6 - DD
DD (Mine) Sold - 98 XJ Moss Green
(His) - 92 YJ December 2013 YJOTM

Sold - 95 ZJ
Sold - 97 XJ Red
Sold - 98 XJ

USN Jeep Club Hull #36
NAXJA #3700

Originally Posted by RacerX View Post
WTF is Clockspring??? my Jeep has digital clock
AmbuGrl is offline   Reply With Quote Quick reply to this message

Quick Reply

Register Now

In order to be able to post messages on the 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.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
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.

Thread Tools

Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. is not in any way associated with Jeep or the Chrysler Corp.