I have had this annoying evap code that is common on these trucks. I smoked it and found the gasket at the solenoid valve on the canister was leaking. Put some gasket sealer on it and all is right with the world again. Additionally my rough idle went away. Hope this helps someone

 

Thank you for sharing. By the way, what is the connection between rough idle and a leaky canister vent valve?

 

maybe coincidental, maybe air entrainment into the fuel system.

 

Paker - I was wrong

CEL is back - mother goose that's irritating.

I am going to figure this out yet and post the results here.

 

finally got around to doing some other testing. The valve under the hood on the firewall has an ohm reading of 33.4 ohms which according to the sticky is acceptable. Also there is voltage on the connector side - that's all good. A inspection of the hoses in that area also look good as far as a visual inspection goes.

 

forget to mention, months ago I replaced the gas cap with OEM. Ruling that one out, but I did see other posts where the mounting ring the cap threads into could crack. Going to check that now.

 

gas cap ring is solid - no cracks

 

moving on to the vent valve. Anyone know what the resistance reading should be on the valve?

 

i replaced the filler neck today due to the aforementioned code. I pressure tested it. The filler neck had some pin holes in the steel, at the end of the rubber hose after the clamp. It was like it was a collection point for rust. I also needed to replace the rubber which I did not account for. Fortunately NAPA has the hose - not cheap and not molded. So if you plan on replacing your filler neck order the hoses - NAPA has it, but it was $20 a foot. I only needed about 11 inches, but it was not molded. The molded hose relieves the stress on the hose and gives a better sealing surface. I went for it and will let you know how it ends up.

 

Yea they sell the complete assembly's on e bay, I'm on my 3rd lol, comes with everything but the fuel cap. They rust and pin hole up after about 5 years if your in a high road salt environment. No protection so they get blasted during the winter. Probably should under coat it, although I never have.

I've attempted the hose methods, not really a good fix when they begin to rust up. I mean you end working on it again within a year or so.

So I spring for the complete assembly when it comes time, I'll see if I can find one real quick....

Yea here's one, but I fish around on e bay and find them cheaper if I can. And just in case you didn't know this was an option, -

http://www.partsgeek.com/fjxtstf-for...el+Filler+Neck

Btw, I know what year your truck is, but when I had EVAP codes, the rear canister was discontinued at the time, they plug up and leak from the rear. To by-pass and eliminate the code you have to disconnect the rear vent tube. I think I have a diagram.... yea #9 is what you have to disconnect to clear the code,



There's an odor disc inside of it, that plugs as well lol. I had to do it 12 years ago or so. This connects behind #9, the disc plugs and can't purge. It forces the system to leak elsewhere. Just yank it off the back, you'll see the disc.