2017 journey gt P0456

[skulnick04]

We bought this car just 2yrs ago. After a few months this code persisted. So I replaced fuel cap, vapor canister purge valve, and the "box towards the gas tank". Forgot what it's called (leak detection pump)? 

 

After that it was many more issues (battery sensor (replaced twice) and still kept getting battery saver. Finally I dug way deep and cleaned/replaced every battery/ground connection I could. That has kept the battery saver gone for a few months now. But, I already have new 2ga battery wires/terminals to replace the junk 8ga stock stuff. 

 

 

Still doesn't answer the evap/gas cap bs. 

 

According to my wife it depends on what gas station/pump she uses. But either way it's more frequent now. 

 

It's the wife's/family hauler fyi. Maybe once a week I use it for my little boat and drive it 10miles. 

 

[Dean H]

You need to get the system smoke tested. 

 

Fill it up with smoke and look for leaks.

Edited July 20, 2025 by Dean H

[Dean H]

This is a smoke machine on Amazon. 

 

https://a.co/d/5xvSmeW

 

 

[luzmina]

I have the P0456 on mine still on the factory warranty, dealer replace the purge valve, canister and update the ECM 2 or 3 times and the code always returned, after warranty expired I change the same parts again and the code returned, finally I replaced the gas cap with a OEM also I sanded the filler neck with 1000 sand paper and greased with brake pads grease.  No more P0456 in the last 8 years.