Originally Posted by jtfoxman
I'm wondering if a leak in my fuel filler neck will cause these codes. I think I may have one back there.
I really doubt it.
Leaks in the tank area cause P-codes 0441, 0455, 0456, 0457, 1442, 1455. This is checked by applying a specific vacuum to the tank, closing it off and then measuring the rate at which the vacuum changes.
The P0443 is for an electrical problem with the Canister Purge Solenoid (or its wiring) and P1445 is related to an electrical problem with the Purge Flow Sensor (or its wiring). Since it appears that these components have been eliminated by swapping them out, it would seem that the next thing to check is the wiring between them and the PCM. It is extremely unlikely that the PCM itself is causing any of these codes.