Recently had check engine light come on. Autozone checked code P144a could not find in their book told me to check with dealer. After some research think might be Evaporative Emission Canister purge valve according to a ford tsb. Anyone else had this issue?
You need to consult the factory PCED and WSM for your specific vehicle to diagnose and repair.
Not to be a wet blanket, but this fault is likely to be beyond the scope of the casual DIYer as it requires special test equipment and procedures. AutoZoners certainly won't be of much help.
The possible good news is that the evaporative emissions warranty might still be in effect, depending on the age and mileage of your unidentified Mariner. See your warranty paperwork....