Hello Guys,
I almost hate to post in the tech section with issues but I am having a hard time diagnosing a issue. Yes, before anyone asks, I have explored the search function thoroughly. I do quite a bit of reading here but no posting.
I have code P0446 currently.
https://blazerforum.com/forum/diagno...plained-35143/

To backtrack a little I have had this code for a long time but it wasn't bothering me. Well, I am going to sell my vehicle soon and I wanted to fix it. I started by changing the purge solenoid. That did not fix the issue. I replaced the vent solenoid. A friend used a bi-directional scanner and command opened the sensor so everything appeared fine. I drove the vehicle for 200-300 miles and no code. Everything was peachy and I am preparing to sell the vehicle.
I went to the emissions place and they said my gas cap was bad so they gave me a new one. It passed emissions at that point in time.
Anyways the code popped up last night again!

Essentially I have replaced:
Purge solenoid
Vent solenoid
Gas Cap
Cleaned vent inlet tube

Side note: Reading other threads many connected fuel pump issues to the code. I have a replacement ac delco that has been there for at least 2 years now.

I still need to check voltage, check lines going to charcoal canister, and make sure to blow out the charcoal canister. Other than that I am not too sure.

Could I be given any helpful info guys?
Thanks,
Brian