P0446 and P0455 codes

[Caric67]

I have a 2008 Explorer, Eddie Bauer, 4.6L, v8 that has the CEL on and throwing both P0446 and P0455 codes. The gas cap light is on as well. I have replaced the gas cap and reset the codes and now they are back. CEL occasionally flashes and sometimes the engine runs rough, it's fine after it warms up though. What's the next step? Should I replaced the Vapor Canister Purge Valve or Vapor Canister Vent Solenoid first? Other thoughts? Thank you!

 

[Flag Gibby]

If it was the canister then you would have a hard time filling up the vehicle. It sounds like it could be the vent valve. However, you need to test the vent valve to see if it is working properly and verify that you don't have a system leak somewhere else.

Edit: FYI, the vent valve is sold as a complete unit with the solenoid and valve in one so if one is bad the whole thing is bad. Also, there is a vapor management valve under the hood that can cause the P0446 code too but typically is not the problem. I doubt that it is a problem in this case since you have a P0455 too.

 

[Caric67]

Thanks for the quick reply! I have had no issues with putting gas in the vehicle. Which part do I start with? On RockAuto the Vapor Canister Purge Valve http://www.rockauto.com/catalog/moreinfo.php?pk=2339628&cc=1441671&jnid=486&jpid=0 or the Vapor Canister Vent Solenoid http://www.rockauto.com/catalog/moreinfo.php?pk=3065532&cc=1441671&jnid=487&jpid=0 or both?

 

[Flag Gibby]

Ok, what they are calling the purge solenoid is the vapor management valve from under the hood and I don't think to be the culprit due to the additional P0455 code. I would pull the canister vent valve/solenoid (by the gas tank) and test it to verify that it is the issue before replacing it because sometimes it can just be corrosion on the connectors causing the problem.

 

[StevenStebo]

On my 06 V8 the fuel vent line (aluminum) meets a rubber hose that goes to vent valve (green shrader valve cap UNDER THE HOOD) on the drivers side. That hose cracked on the underside where it connects to the aluminum line. I cut off 1.5 inches and hooked it back up.

I was getting the same codes a few years ago right before emission testing!

AAaargggGGHH!

 

[Flag Gibby]

I agree, that is why I said to also check the system for leaks back in post #2 and verify components before replacing.

 

[rathrbcruisin]

I have the 0455 code too, replaced the gas cap hoping that was it. It wasn't. What ended up being the problem here?

 

[Caric67]

Mine was the wiring harness to the purge valve solenoid. One wire was totally rotted off. I had ordered a wiring harness and purge valve solenoid from Rock Auto. They were not the right parts so I "fixed" the old harness until I was able to get a new one.