PO446 code

hey guys I recently got a 446 code for the evap valve being stuck open or closed. any quick things I can check to trouble shoot or an easy way to fix the issue? thanks!

 

I chased this one on my Taco for several weeks. If it is just 446 then a close inspection of all the evap lines and hoses from engine compartment switches to Evap canister and fuel tank is the first thing to do. The evap valve on the canister can be checked with a 9v battery to see if it is clicking. Also check connector wiring at canister valve. I live in the rust belt and it ended up being bad valve on the canister-all rusted up. Had to lift the bed to replace the complete canister ass'y due to rusted bolts. If there are any other evap codes with the 446 then other things will need to be checked before just throwing expensive parts at it.

 

My truck was throwing this code for over a year. Just before pulling the trigger on a new canister, I tried a new gas cap for the second time. That was about 10,000 miles ago. Still no code!

 

Yea-I went that route also. First with an OEM cap then a Stant. Even tried gently sanding small pits on sealing edge of filler neck. Didn't work for me but I'm glad it did for you!