EVAP code causes and fixes - 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 05-14-2014, 09:39 PM   #1
Jeeper
 
Join Date: Jun 2011
Location: Northern NJ
Posts: 256
EVAP code causes and fixes

My 2000 TJ (6-cyl) has been throwing an 0455 code at odd intervals.

You'd think, it being a "large leak" code, that it would just come back after I reset it. But it doesn't. Sometimes it goes 1000 miles or more before the light comes back on. I've also gotten a simultaneous "small leak" code -- and I don't see how the system can tell there's a small leak if there's already a large leak. So I'm suspicious of EVERYTHING.

I've checked all the under-hood hoses and they look OK; I also replaced the gascap (goddam factory cap cost me $26 at the stealer's !!!)

SO -- what's next ? Take it in for a "smoke test", or replace whatever passes for a sensor ? (And just WHAT is the sensor?)

Thanks...

PeteH is offline   Quote Quick Reply
Old 05-14-2014, 09:46 PM   #2
Jeeper
 
DoubleOught's Avatar
 
Join Date: Feb 2014
Location: Nashville GA
Posts: 1,168
I chased this on a 02 Dodge truck for a year and it turned out to be a bad PCV valve but our TJs don't have one. Does the oil filler cap seal good? Also, make sure the breather tube/elbow near the rear of the valve cover isn't plugged or cracked. Also have seen E3 plugs on a 4.0 cause these codes (friend of mine). Again, never seen it on a TJ but many GMs will get EVAP codes when the purge valve is failing. Maybe check the vent line from your filler neck to the tank also.

DoubleOught is offline   Quote Quick Reply
Old 05-14-2014, 10:30 PM   #3
Jeeper
 
Ryan Angela's Avatar
 
Join Date: Sep 2013
Location: Yorkville IL
Posts: 483
Leak detection pump. I chased that code for months. Took it in for a smoke test, and they found the inside of this pump was packed solid with mud.
__________________
'01 60th anniversary ed. TJ 4.0 auto, 2.5" RC SL, 1" MML, 31x10.5x15 Duratracs, weekend toy.
Ryan Angela is offline   Quote Quick Reply
Old 07-08-2014, 08:56 PM   #4
Jeeper
 
TMTMTL's Avatar
 
Join Date: Jun 2013
Location: Enterprise, Al
Posts: 74
Ryan- can you explain all of this in a little more detail? I'm getting the same code and was told exactly what you just said.... I just have no clue what you're talking about. Thanks in advance!
TMTMTL is offline   Quote Quick Reply
Old 07-08-2014, 10:15 PM   #5
KMG 365

WF Supporting Member
 
Sccafire's Avatar
 
Join Date: Oct 2011
Location: 92 miles from the Rubicon Trail
Posts: 718
A smoke test is performed usually by a mechanic with a smoke machine in the shop. There is a port on your evap system that the machine hooks up to. They pressurize the evap system with said smoke machine. Then obviously where there is a hole/crack or whatever smoke will come out.
__________________
Scott
Sccafire is offline   Quote Quick Reply
Old 07-09-2014, 05:38 PM   #6
Jeeper
 
Ryan Angela's Avatar
 
Join Date: Sep 2013
Location: Yorkville IL
Posts: 483
Quote:
Originally Posted by TMTMTL View Post
Ryan- can you explain all of this in a little more detail? I'm getting the same code and was told exactly what you just said.... I just have no clue what you're talking about. Thanks in advance!
I'm by no means an expert on this, just repeating an explanation passed on to me.
At each start up, the leak detection pump (LDP) pumps a slight bit of air into the vapor recovery system to check for leaks. If it notices a immediate drop, it will continue to pump air to determine large vs small leak. If the pump is bathed in mud and water, it may hinder its operation. On my '01, the LDP is under the hood on the drivers fender. Other years, it is located in the rear passenger fender, behind the plastic liner. I forget the price on the new pump, but it was well worth pulling off the old one and cleaning the gunk out of it. Trace all the lines out and check for dry-rot while your in there.
__________________
'01 60th anniversary ed. TJ 4.0 auto, 2.5" RC SL, 1" MML, 31x10.5x15 Duratracs, weekend toy.
Ryan Angela is offline   Quote Quick Reply
Old 07-09-2014, 05:50 PM   #7
Jeeper
 
Join Date: Apr 2013
Posts: 2,024
That goberment mandated pump is only on California emissions TJ at least thru 2004
Not so sure about 05 06

My 04 federal emissions rubi no such pump
My 98 calif emissions sport has that pump

Digger84 is online now   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




» Network Links
»Jeep Parts
» Featured Product

All times are GMT -5. The time now is 05:58 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