Scan Tools to check backfire issue - 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 06-15-2008, 10:47 PM   #1
Jeeper
 
Kodiak Commando's Avatar
 
Join Date: Apr 2008
Location: Clovis, California
Posts: 29
Scan Tools to check backfire issue

Guys,
I had a wierd event take place on my 05 Rubicon Unlimmited the other day. It has the automatic and has 47k miles on it. I was pulling a tent trailer up a steep hill (out of Oakhurst, CA) and there was what sounded like a backfire. The check engine light came on and power was down to 15% of what it was. I disconnected the battery to clear and reset the computer and it worked much better but still not 100%. It got me home anyway. It ran well all week without throwing codes so we took it wheeling yesterday. You guessed it, the check engine light came back and the power, while not as bad as the first event, is down 20% or so.
Anyone have recommendations on a code reader? I don't want to clear the check again without seeing what was reported.

__________________
Fred Whorff
2005 Rubicon Unlimmited
1967 Jeepster Commando
1991 Grand Wagoneer
1951 Willys Pickup
Yes it's a disease of epic proportions! http://www.4x4him.com
Kodiak Commando is offline   Quote Quick Reply
Old 06-15-2008, 10:49 PM   #2
Hacks off Parts while Lit
 
whitebuffalo's Avatar
 
Join Date: May 2005
Location: The Sandhills of South Texas
Posts: 2,290
does the key on off trick work on jeeps? turn the key on, then off, then on, then off, then on again and it shows the codes (on dodge OBD2 at least)

__________________
'90 YJ, ford 8.8, SOA, lincoln front, aussie rear, 4.88s, swampers.
whitebuffalo is offline   Quote Quick Reply
Old 06-15-2008, 11:29 PM   #3
Jeeper
 
Join Date: Nov 2006
Location: Chicago, IL
Posts: 8,286
Send a message via AIM to Triple88a Send a message via MSN to Triple88a Send a message via Yahoo to Triple88a Send a message via Skype™ to Triple88a
go to autozone, they should have free code checks. They will read your codes for free.

Once you get the codes you can find what it really is.
Triple88a is offline   Quote Quick Reply
Old 06-17-2008, 11:42 PM   #4
Jeeper
 
Kodiak Commando's Avatar
 
Join Date: Apr 2008
Location: Clovis, California
Posts: 29
Quote:
Originally Posted by Triple88a View Post
go to autozone, they should have free code checks. They will read your codes for free.

Once you get the codes you can find what it really is.
Thanks for the lead! I went to autozone and borrowed their code reader. It showed PO431 Warmup catalyst below threshold (bank 2). Headed to the dealer and am having them replace it under California Emmissions Warranty. Of course that doesn't explain why there was enough fuel in the exhaust to ignite and blow it out! We'll see what happens after I get it back. Ahhhhh Jeep mysteries, you gotta love em.
__________________
Fred Whorff
2005 Rubicon Unlimmited
1967 Jeepster Commando
1991 Grand Wagoneer
1951 Willys Pickup
Yes it's a disease of epic proportions! http://www.4x4him.com
Kodiak Commando is offline   Quote Quick Reply
Old 06-19-2008, 12:15 AM   #5
Jeeper
 
Kodiak Commando's Avatar
 
Join Date: Apr 2008
Location: Clovis, California
Posts: 29
So the answer is in! The injector wires melted from the heat from the warm up cats. That's the reason for the backfire as it was dumping fuel due to being shorted "on". The explosion and short freaked the computer into limp mode. When I disconnected the battery, the computer was reset and the injectors worked reasonably enought to get home. The dealer replaced all three cats and the exhaust from the muffler forward and fixed the melted wiring. I noticed the routing is safer that the way it came now as well.
Moral of this story, check your injector harness proximity to the exhaust!
__________________
Fred Whorff
2005 Rubicon Unlimmited
1967 Jeepster Commando
1991 Grand Wagoneer
1951 Willys Pickup
Yes it's a disease of epic proportions! http://www.4x4him.com
Kodiak Commando is offline   Quote Quick Reply
Old 06-19-2008, 06:18 AM   #6
MOz
Jeeper
 
MOz's Avatar
 
Join Date: Apr 2007
Location: Poconos
Posts: 2,484
Good information.
__________________


It ain't no fun unless you get some of it on you.
MOz is offline   Quote Quick Reply
Old 06-19-2008, 01:14 PM   #7
Jeeper
 
Join Date: Nov 2006
Location: Chicago, IL
Posts: 8,286
Send a message via AIM to Triple88a Send a message via MSN to Triple88a Send a message via Yahoo to Triple88a Send a message via Skype™ to Triple88a
good to know, what did she cost you for the repair?

Triple88a 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
Summer 2008 Issue of JPFreek Magazine Available Now txoutdoorx4 General Jeep Discussion 1 06-25-2008 10:25 PM
New Issue of JPFreek Adventure Magazine available now! txoutdoorx4 General Jeep Discussion 2 10-11-2007 12:53 PM



» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 04:48 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