i keep getting this code. replaced gas cap and checked all hoses still coming back. ive read every frign post about it i can find.


most if not all pointed to what appears the only electro mechanical parts in the system. a vapor management valve under the hood. then a solonoid in the back of the truck underneath.

the parts guy found a listing vapor cannister purge valve and a vapor purge solonoid. ordered the parts and they are the same part. the two parts that arrived are the one under the hood.

so i put on one of them, but where do i get the other part? cant find one or even the mention of one at any auto parts site like rock auto. oddly enuff rock auto has two different names for the same part also. this is making me a angry man


truck is 1998 f150 4x4 with 4.6 liter engine code w

 

stop throwing parts at it and find someone that can smoke the evap system and find the leak. and btw, i have replaced alot of new aftermarket gas caps for p0455. that code is for a leak, not always a failed electrical part. could be rusted filler neck, rusted tank, hole in evap line. canister vent or purge not fully closing, faulty fuel tank pressure sensor. all those parts combined will cost alot more than the diag charge at a good shop or dealer.

 

spoken like a true stealership employee. nah ima go it alone

 

Well go a head and never get it fixed since you can't even find the right part.

 

um thats why im here.

thanks for not helping in any way

 

- You figure it out yet ?

 

You expect help here when you slam a competent dealership tech who has given you excellent FREE advice? You really are on your own now.............

 

if you read my post you would know i never asked for advice. what i asked for was where to buy a vapor cannister solenoid. so now what are we talking about again?

 

i thought for the benefit of others that may enter po 455 in the search box id post that the canister vent solenoid seems to be a dealer only part. i changed the vapor purge valve and it didnt stop the code from coming back.

the part number from ford for the solenoid above the axle is f75z-9f945-ca. replacing it solved my code. the cost was about $100.

i learned something the old fashioned way, trial and error thats the way i like it.

 

Water gunner, what are you going to do next?
If I were you I would find out what the code is alerting you to.
Here it is; it is classed as a 'large' leak in the tank hardware or connecting lines.
The test is done while the vehichle is in drive cycle, not at idle.
A vacuum draw down is attempted then measured with a sensor.
If the sensor cannot detect the correct vaccum draw it is logiced a failure.
You have a leak to be found or the sensor/valving is faulty.
Don't be such a hard head about it.
Good luck.

 

thank you baby jesus for putting mrs matzedar my 6th grade teacher in my life. reading comprehension is good!

 

Wow I am afraid of this website. I am 77 years old and shell shocked enough from Viet Nam. I have a 98 f150 4.6 i am trying to keep alive until June about 3 months and failed emission. PO401. I made a lucky guess and got a DPFE for $18 and that code went away. The other code is PO455. If you know what an interlock device is which I have had on 7 years and comets off in June. I can't back probe or do any test with key on engine off. Machine won't let me. I have to start it if I turn on the ignition. Last year I had a fuel tank put on $550. This old truck is a total loss claim and worthless to sell but runs great with !##K miles on it. Am I wasting my time to change the Vapor Management Valve on the firewall. Where would you connect a smoke machine? The vmv has a test port but I don't have a schrader tool if that is what I need. Can I pull the lower emission hose off and smoke it through there? Don't start hating on me. My dad was a great mechanic and told me to never touch a car unless I wanted low pay and a bad back. Things have changed since then.

 

https://www.autocodes.com/p0455_1998_ford_f150.html

https://www.stangnet.com/images/stor...s/03-20-03.pdf

If you can't properly troubleshoot this for whatever reason, it can get expensive shotgunning parts at it, and it may be cheaper in the long run to have a pro do it. With that said, have you tried the obvious?

Missing or loose fuel cap
Incorrect fuel filler cap used
Fuel filler cap remains open or fails to close
Foreign matter caught in fuel filler cap

A fuel cap is cheap. A VMV is not, and the problem is just as likely somewhere between it and the tank than the VMV itself.

EDIT: FYI, if the P0401 comes back, the EGR passages in the throttle body elbow are probably plugged. Remove the throttle body and elbow, use carb cleaner and pipe cleaners to clean them out. It can also be caused by a rotten EGR pipe at the driver's side exhaust manifold. That's a real pain to change, if the threads on the nipple are rotted, it's almost impossible to get the nipple out of the manifold. If the threads are okay, replacing the pipe is pretty simple.

 

Since the fuel tank was recently replaced, I'd put inspecting all of its connections on the list, right after checking the fuel cap seal and installing a new Motorcraft cap as glc suggested.

Probably. The VMV would be among the LAST things on my suspect list. The vent valve and its plumbing would be a lot higher on the list. Crap can get into the vent valve and prevent it from sealing when commanded to close.

By the time you figure out how to make (or buy) a smoke machine and test port adapter, you'd likely have been better off paying a shop a diagnostic fee to do the test for you. Just a suggestion....