Ok, so I bought this trusty old truck recently ('96 Ranger 4.0 4x4 MTX w/290K on the clock!) and it had a CEL displaying. She seems to run just fine, but I finally put the OBD-II reader on and pulled a P1443 code. I read a few things online that said this may be due to some Engine Evaporator Valve or something that is hooked up to a Purge Valve? Where would this be located, and how do I test it?

 

Welcome to the forum


EVAP system sucks(.............lol..........)air from the gas tank to prevent gas fumes from polluting the air.

So what you have is a hose from the intake manifold(vacuum source), it will run to an EVAP pressure sensor, then a hose from pressure sensor to the EVAP Solenoid, computer opens EVAP solenoid to suck gas fumes from the gas tank to the intake, pressure sensor tells computer if there is a vacuum first(engine running), and then when solenoid opens if pressure drops a bit but holds steady, so no leaks in the system.

EVAP solenoid has a 2nd hose to the EVAP Canister, it has charcoal inside to filter the fumes.
All the above is in the engine bay, usually drivers side

There is a hose from Canister all the way back to the gas tank.

Intake manifold==========Pressure sensor==============Solenoid=======Canister======= ===============================Gas tank

Pressure sensor and solenoid can be in reverse order, just depends on the system

Couple of things, gas tank should be air tight when gas cap is on, so no gas cap gets P1443, because it can't hold pressure.
Cracked Vent or filler hose on gas tank, same thing.
Cracked vacuum hose or canister, same thing can't hold pressure.

Could be the EVAP solenoid isn't working, you can test it with 9volt battery or the truck battery, should click when it has + and - voltage

Could be EVAP sensor, but this is the very very very last thing to change.

P1443 takes a while to clear, CEL will stay on even AFTER you have fixed the problem.
After making any changes you need to drive the truck for 3 or 4 days and keep fuel level between 1/4 and 3/4, and see if CEL goes off.
A Ford Dealer can reset P1443, if problem is fixed, but best to keep your money and just wait the few days