Hi Guys,

I'm wondering if I can get some advice on how to proceed with my P0446 code on my 2007 Suburban. I had the slow filling issue as well as P0446 and a large evap leak code (P0455) originally, so I replaced the EVAP vent valve/solenoid above the spare tire. This fixed my slow filling issue completely and my check engine light went away for about a week. It came back today with just the P0446 code. I went to the gas station on the way home and it fills up fine still so I don't think the part I replaced is failing. I know a lot of guys replace the purge solenoid in the engine bay as well for this problem, but I often hear that there's starting issues involved with that which I don't have.

I would appreciate any advice.

Thanks

 

if the purge was stuck open you would have a hard st art after refu eling do to f uel f umes passing into the intake manifold.
the po446 dtc is checking for a blocked evap path.
it does this by commanding the purge valve open and watching for vacuum build up from the fuel tank pressure sensor. if to much vac b uillds...ie ftp sensor 1.5 volts or higher...the dtc sets.
you need to check the ftp sensor and see if the voltage c hanges d uring purge. if the reading is stuck at 1.5 with the engine off and gas cap off...the sensor may be bad.

 

Thanks for the suggestion, I'll take a look at that tomorrow and see if that looks like the issue.