P1443, P0174 Ford Thunderbird

As always, any/all help is greatly appreciated.

I have 1997 Ford Tbird, 4.6L with (2) service codes. P1443, “No Definition Available”. I had this code about a year ago, and had a mechanic look into it. He said it is typically an Evap code related to the fuel vacuum system. He recommended replacing the fuel cap, which I did. This did not correct the problem. I took it to the mechanic, where he found that the Evap canister was full of gasoline. He replaced that with a used canister from a Mustang that was being parted out. The code did not come back for several months. It is back. I am contemplating a replacement of the evap purge valve. Any thoughts on this?

More recently, I have a P0174 code, “System too lean(bank 2)”. The engine is pinging on acceleration, and runs a bit rough. I believe this is pointing to an oxygen sensor, but not too sure. Again, any thoughts and ideas are appreciated.

You need your mechanic to do some troubleshooting, or, another mechanic. He may be great in changing parts; but, that’s inadequate when the problem is more complex than that. Here is a little article on your problem: http://free-auto-repair-advice.blogspot.com/search/label/EVAP%20codes
DTC P1443 is defined as:Evaporative Emission System Control Valve has low or no flow.
DTC P0174 is defined as you stated: System too lean on bank 2 (LEFT side) of the engine. This DTC may be a result of DTC P1443. Yep. If vacuum is leaking, through a hose, a valve, or elsewhere, allowing unmetered air to go to the cylinders nearest the leak, you could get those codes. Uncontrolled air flow (“leaks”) upset the air/fuel mixture going into the engine.