im glad ive finally joined these forums, its already helped me with my other troubles. but currently im stumped at this point. ive been working on a 1996 ford f-150 5.0L and we've(me and my stepdad) have been changing every single sensor in the book,but still end up coming short on solving this issue. we need the truck to haul our trailer but since it cant pass its smog without clearing the code, we are at a standstill. please if anyone could help me out it would be deeply appreciated.

 

http://engine-codes.com/pdf/codes_pd...ode=p0443_ford

 

Purge solenoid is supposed to open (at a good time) to allow excess fumes from the tanks to be drawn into the engine via the intake and burned off. You have a line from the tanks to the charcoal canister (line crosses from left side to right side near the back of the cab) and another line from there to the intake, with a purge solenoid (valve) in that line.
Somewhere in that system something's maybe not hooked up or not working. Or the PCM isn't telling it to open (which could be a sensor, usually heat related ?).
Check the whole purge system out first off.