Evap control problem

[Lorraine1982]

I'm seriously at a loss. Keep getting the code p0446 replaced purge valve, charcoal canister, vent valve solenoid, blew the lines. Now says maybe the fuel tank pressure sensor. I've already dumped too much money on this problem what's some sound advice as to actually fix the issue ( side note only takes 1-4 days max to throw the code back on)

[Black02Silverado]

Next is a smoke test to see if any of your lines has a crack in it. I had the code and found the one line coming from the fuel tank was cracked.

[txab]

Next is a smoke test to see if any of your lines has a crack in it. I had the code and found the one line coming from the fuel tank was cracked.

 

 

+1

[PS4570]

Last time I had this code, I replaced the gas cap. Problem solved. I'm usually not that lucky!

[Lorraine1982]

Thanks. Already had smoke test done prior to work ( was told charcoal canister) gas cap replaced but not a certified gm wondering if that makes a difference. ( got it at napa) maybe worth another smoke test gotta wait on more money

[tbarn]

P0446 is not a "leak" code. It is a plugged system or pressure sensor code.

[Lorraine1982]

So with that being said should I go for the fuel tank sensor that it is now telling me is a likely cause

[Black02Silverado]

So with that being said should I go for the fuel tank sensor that it is now telling me is a likely cause

Sounds like that is next in the troubleshooting tree.

[Daddyhog]

I have a 2007 NNBS Sierra 5.3 Flex Fuel Z71 ext cab and went through the same problem code. I replaced purge valve at intake manifold, purge solenoid canister (in front of fuel tank), fuel pressure switch (top of tank), and still would throw Po446. I replaced the vapor charcoal canister and no more codes. Mine was also extremely difficult to put fuel into tank. I hope this helps you.

[Lorraine1982]

I have a 2007 NNBS Sierra 5.3 Flex Fuel Z71 ext cab and went through the same problem code. I replaced purge valve at intake manifold, purge solenoid canister (in front of fuel tank), fuel pressure switch (top of tank), and still would throw Po446. I replaced the vapor charcoal canister and no more codes. Mine was also extremely difficult to put fuel into tank. I hope this helps you.

Thanks I'll throw that at my mechanic see if that's a part we have replaced already