P0456 Check Engine Light & Clear Code - JeepForum.com
 
LinkBack Thread Tools
post #1 of 6 Old 08-20-2019, 10:22 PM Thread Starter
Penemonie
Registered User
2006 WK 
 
Join Date: Feb 2015
Posts: 43
P0456 Check Engine Light & Clear Code

A few days ago my wk prompted me to "close fuel cap". It eventually was replaced by the check engine light. OBD reader shows p0456 (small leak). I replaced the fuel cap (old one was indeed not as tight compared to the new one) but the check engine light still persists after I drove two minutes in my apartment complex. Should I clear the code and see if it comes back or if I clear the code it will be permanently gone even if the problem is not fixed? I know this issue has been addressed in other threads but I just want to know if fuel cap replacement is the solution for me. Thanks!

Penemonie is offline  
Sponsored Links
Advertisement
 
post #2 of 6 Old 08-21-2019, 06:23 AM
jtec
Registered User
2014 JK Wrangler 
 
Join Date: Oct 2017
Posts: 6,314
The system will need to run the tests and if no issue it will turn off the CEL.
There will be several conditions met for the system to run the test IIRC - 3 good tests, a overnight (temp soak), fuel level, And maybe others.....

Suggest you drive for 2 days with a overnight to satisfy the soak, temp, sleep change- the term escapes me at the moment...

Don;t top off tank.

When I see the price of OEM I think aftermarket.
When I see the quality of aftermarket I think OEM.
jtec is online now  
post #3 of 6 Old 08-22-2019, 06:26 AM
Walt
Registered User
2008 WK 
 
Join Date: Oct 2009
Location: Midland
Posts: 2,395
Quote:
Originally Posted by jtec View Post
The system will need to run the tests and if no issue it will turn off the CEL.
There will be several conditions met for the system to run the test IIRC - 3 good tests, a overnight (temp soak), fuel level, And maybe others.....

Suggest you drive for 2 days with a overnight to satisfy the soak, temp, sleep change- the term escapes me at the moment...

Don;t top off tank.
To Penemonie:



It may take the PCM several "good trips" (no DTC) for the MIL to extinguish. You can clear it manually if you have a code reader/scanner.

It is important not to overfill these WK gas tanks as liquid will get into the vent gas portion and either set a DTC or ruin some of your leak detection components. When the gas pump nozzle kicks off, stop filling.

HEMI CLUB MEMBER #45; SILVER WK CLUB MEMBER #13
'08 WK GC Limited. 5.7L HEMI. Quadra-Trac II. Bright Silver Metallic. Class IV hitch.
Michelin LTX M/S tires. Fumoto oil drain valve. Billet Technology oil catch can.
Walt is offline  
 
post #4 of 6 Old 08-22-2019, 06:08 PM Thread Starter
Penemonie
Registered User
2006 WK 
 
Join Date: Feb 2015
Posts: 43
Quote:
Originally Posted by Walt View Post
To Penemonie:



It may take the PCM several "good trips" (no DTC) for the MIL to extinguish. You can clear it manually if you have a code reader/scanner.

It is important not to overfill these WK gas tanks as liquid will get into the vent gas portion and either set a DTC or ruin some of your leak detection components. When the gas pump nozzle kicks off, stop filling.
I do have the habit of overfilling... Day two of short-trip commutes. Houston right now is very humid and maybe this is why the light is still on. Will keep updating. Thanks!
Penemonie is offline  
post #5 of 6 Old 08-23-2019, 06:33 AM
Walt
Registered User
2008 WK 
 
Join Date: Oct 2009
Location: Midland
Posts: 2,395
Quote:
Originally Posted by Penemonie View Post
I do have the habit of overfilling... Day two of short-trip commutes. Houston right now is very humid and maybe this is why the light is still on. Will keep updating. Thanks!
Humidity is not a factor.

Some people try to fill the tank up into the filler neck. On the WK, there is a vent line from the line line over to the emissions system (behind driver's side rear wheel). Liquid flows into that system when it is only designed to handle gasoline vapors.
That can ruin your control valve, pump, or the charcoal canister that captures fuel vapors..

For your MIL, make sure the filler neck where the gas cap seals is clean and clear of debris. Also, check the hose connections to the evap/purge solenoid under the hood in the engine compt. It is located between the electrical / fuse boxes and the battery on mine.

HEMI CLUB MEMBER #45; SILVER WK CLUB MEMBER #13
'08 WK GC Limited. 5.7L HEMI. Quadra-Trac II. Bright Silver Metallic. Class IV hitch.
Michelin LTX M/S tires. Fumoto oil drain valve. Billet Technology oil catch can.
Walt is offline  
post #6 of 6 Old 08-27-2019, 09:52 PM Thread Starter
Penemonie
Registered User
2006 WK 
 
Join Date: Feb 2015
Posts: 43
UPDATE: After replacing the fuel cap, I had a few 10-min city trips for a few days and the CEL was still on but after putting >1.5hr highway driving on a Saturday, it went away! Thanks everyone!
Penemonie is offline  
Reply

Tags
check engine , check engine light , fuel , obd 2 , OBD II

Quick Reply
Message:
Options

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:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.



Email Address:
OR

Log-in











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