Engine code error

[TheOKCAggie]

Ok my check engine light just came on for my 04 TJ 4.0. Using the ignition key got the code 456 'A small leak has been detected in the evaporative system!'. What the heck does that mean and what do I need to possibly fix or replace?

 

[Jester32]

Gas cap could be leaking. Most common problem on those.

 

[Jester32]

Tighten it at clear code.

 

[Mikey4x4]

I just got a new gas cap mine never popped a code but failed Texas inspection so they do go bad. it's 03 TJ

 

[SteelHeadz]

I agree with the fuel cap since it's a small evap. leak . Other causes for a small leak is a cracked vac. lines to and from the LDP(leak detection pump), purge solenoid valve and or canister. In some cases, either the purge solenoid valve or the LDP will have an intermittent small leak and will throw a P0456. I would recommend if the fuel cap is good, check the vac. lines first on all the mentioned component particularly where the rubber hose is slipped to the component fitting. It usually cracks where it's stretched.

 

[TheOKCAggie]

Thanks I will check everything tomorrow and see if I can narrow it down.

 

[TheOKCAggie]

Thanks gas cap fixed the problem

 

[Mikey4x4]

Simple fix is always good have a good new year