Lincoln Navigator P144C: Meaning, Causes, + Diagnosis

P144C Lincoln Navigator

P144C is a Ford-only DTC trouble code, and as such, it applies to your Lincoln Navigator. It indicates that the EVAP canister purge check valve is not performing within spec.

P144C is most often fixed by replacing the EVAP purge valve assembly (due to the purge valve being stuck open or closed), which can be a little tricky depending on how tight your Navigator’s engine compartment is.

The EVAP purge check valve is part of the Evaporative Emissions System, which exists to control fuel vapor. Therefore, P144C should not be considered a breakdown risk when it is the only code stored in your Navigator’s PCM.

P144C Definition: EVAP Purge Check Valve – Performance

P144C Meaning Lincoln Navigator

Here’s what happened for you to get P144C in your Navigator:

The EVAP purge valve pulls fuel vapor from the gas tank and sends it into the intake manifold. From there, it burns off cleanly.

Your Lincoln’s PCM performs a test on the EVAP check valve during light boost conditions, one time per drive cycle.

It is checking to see if the fuel tank pressure exceeds the calibrated amount or if the fuel tank vacuum is less than the calibrated amount for a certain amount of time. If it doesn’t see the proper values, P144C is triggered.

P144C Symptoms: Lincoln Navigator

The only symptom you should expect to see with P144C is the check engine light. A failure in the EVAP system should not affect the way your Navigator runs and drives.

Lincoln Navigator: P144C Causes

P144C Causes and Fix

P144C is an increasingly common code on turbo-charged vehicles. Here are the most common causes of P144C in the Navigator:

  • Bad EVAP check valve
  • Bad EVAP Ejector
  • EVAP check valve stuck open or closed
  • Blocked EVAP connection at the intake air system

Check out the video below. If P144C is intermittent, it can be challenging to chase down. You can start by inspecting the EVAP hoses. After that, you can use a scanner to command the purge valve to open and close. Verify that it does.


A bad EVAP check valve often causes P144C in the Lincoln Navigator. Good luck fixing chasing down the problem!