got a filler neck leak code on my 2011 Lariat. I have a couple of questions, maybe you guys can help me out.

What at is the sensor actually measuring, pressure, continuity or something else?

A new filler nexk is less than $100, looks like the problem will be getting the old one out and the new one in. Is replacement the only option? In other words I’m assuming it’s a pin hole from rust in the filler neck could it be anything else?

 

Post the ACTUAL FAULT CODE, not some off-the-wall interpretation.

 

If it's leaking at the filler neck, it's possible that there's something preventing the EasyFuel flap from completely sealing the neck. Take the fueling funnel (which should be with the jack kit) and insert/remove it from the filler neck a few times. I've seen some recommend squirting a little bit of spray lube on/around the flap before you do that, but I don't know if that's a good idea or not.

 

Also, the actual code would be helpful--if they have the code, guys with access to the diagnostic charts can look up the troubleshooting steps for it.

 

If it is the P0442 or P0443 code it could be a Purge valve also, that is on the motor. 35 bucks from rock auto

 

It could be a lot of things. Guessing in the blind is pretty pointless.

 

Fault code is P0442

I vacuum checked the purge valve solenoid last night and have decided to replace it today, will keep you posted. Thank you for the help so far, i appreciate it.

I can't resist...ProjectSHO89 - you need to chill dude. i understand you're mad if you're working on a 1989 SHO, aka trailer park hot rod, i'd be upset too but i would not take it out on others.

 

Mad? I'm not mad. I do diagnostics for a living, guessing is not a valid diagnostic method. Trying to assist on a remote diagnosis with poor input data is a waste of time. Therefore, GOOD data is needed.

The SHOs are long gone...only the screen name remains.

The self-sealing flap the SoonerLS mentioned is your most likely culprit. Try cleaning it first as he suggested.

 

Replacement of the purge valve did the trick, i installed the new valve, reset the CEL and drove it all weekend, no problems.

Thanks for the help.

 

It can take an extended period (days to weeks) of time for the EVAP monitor to actually execute. Keep your expectations in check until you've determined absolutely that it has run and passed. That can be checked by looking at the monitor flags with a scan tool or code reader.