P0446 code not going away

[barcelonaleo]

09 Chevy Tahoe with about 160k miles. CEL came on for P0446 and fuel cap, vapor canister purge valve, and vapor canister vent valve have all been replaced. Now leaning towards a fuel tank pressure sensor but unsure of the readings I’m getting. Hooked up a scan tool and have readings of .274 mmhgs with a slight increase to .465 mmhgs when opening and closing solenoid from 100 to 0. Also, getting readings of only 1.4 volts at the fuel tank pressure sensor through out the test. Would this indicate a bad pressure sensor?

 

[OR VietVet]

Welcome to the forum from Oregon.

You might have charcoal debris in the lines too. I have read many threads about these emission lines and components problems and it seems like what fixes it, is replacing all of it. Otherwise, I see a member say the code went away and it is fixed and then comes back and at the end, it is all replaced.

 

[j91z28d1]

I got a bad oem charcoal canister as well that set a slow leak code. ended up putting the old one back on and the code went away. that's pretty rare for oem parts, but if you didn't use open stuff, it's possible you still have a bad part.