Popped a P0451 code (EVAP switch) on my 18 F150 with 21k miles on it. Does anyone know if this has been problematic for these?

 

Which engine?

 

Oh sorry about that. 2.7L

 

No TSBs or SSMs.

 

Found this:

 

From the PC/ED Manual

P0451 - Evaporative Emission System Pressure Sensor/Switch Range/Performance

Description:

This DTC sets when a fuel tank pressure (FTP) sensor range (offset) concern is detected. The FTP sensor output is offset by greater than 1.7 inches of water or less than -1.7 inches of water.

Possible Causes:

• FTP circuit intermittent open
• FTP circuit intermittent short
• FTP sensor intermittent open
• FTP sensor intermittent short
• Contaminated FTP sensor
• Damaged FTP sensor
• Damaged PCM

Diagnostic Aids:

With the FTP sensor at atmospheric pressure, the FTP PID normally indicates 0 inches of water. Remove the fuel filler cap or, for vehicles with a capless fuel filler pipe, install the supplemental refueling adaptor provided with the vehicle to open the capless fuel tank filler pipe. After installing the supplemental refueling adaptor or removing the fuel filler cap, wait one minute to allow the pressure in the fuel tank to equalize with the ambient air pressure before accessing the PID.

 

Hmmm, my truck didn't come with a supplemental refueling adapter. Is that what that thing is in the video?

 

Just heard back from the dealer, apparently there was a bit of dirt in that flap in the fill pipe. They cleaned it, hopefully that fixes it.

 

It should be behind the passenger seat with your jack.

 

I found it! Thanks!

So it was apparently the flap inside the fuel fill. The dealer said its not uncommon this time of year with all of the crap on the roads.

Thanks again!