Gen 1 P0456 code (emissions systems small leak detected)

All,

2003 ex cab, 226K miles. I get the P0456 code from time to time and do notice a fuel smell around the gas tank - charcoal canister area when I park in my garage. It is more prominent when I fill the tank.

What is the most likely candidate for the leak? The charcoal canister itself? Hoses? Is the only way to service or repair is to remove the bed? Can't see anything but know it is there because of the code and smell.

Thanks!

 

I guess I'll reply to myself. LOL

Had the smoke test done and it ended up being the gas cap. I did not suspect that was the issue because I had a brand new aftermarket and the original with no change so I figured it had to be something else. Wrong. It was the gas cap, both were bad. Bit the bullet and bought Toyota OEM.

 

I learned my lesson and now buy only OEM gas caps. Gently wipe the fuel tank filler tube, gas cap rubber O-ring with a clean windshield towel every time you get gas. You'll be surprised by how much dirt comes off. The cap will last twice as long. You can buy just a replacement O-ring, but I've never bothered trying to change one.

 

Well, here I am today. New OEM gas cap and still have the problem. 0456 small leak detected. Smoke test supposedly indicated leak in the filler tube somewhere. Have to drop the tank or remove the bed to fix.

Anybody seen this before and how hard is it really to replace the filler tube assembly with the bed on?

 

Still sounds like the gas cap. Even a new one can leak, maybe dirty from the manufacturing process, or microscopic dirt/grit on the fill tube inlet? Wipe the cap and fill inlet good, clear the code, try it again. Amazing how dirty they get.

 

Yeah, I tried that on several occasions. I am going to get in there and clean the filler tube and everything else I can get to to see if I can finally actually visually see a moist area. The fumes are strong enough that I would think I would be able to see something. Luckily for me I have a scan gauge that I can simply reset the light on the fly each time. But it is getting very annoying, plus the deer wife complains of the gas smell in the garage