joshglass

Hi all,

I have an '01 XJ and a few days ago it threw a CEL, and upon scanning I had 3 different codes all related to evap system. P0455, P0442, P0456. They are all titled "evaporative emission system leak detected" followed by "(large leak)", "(small leak)", "(very small leak)", respectfully.

A few months ago I had a different evap code pop up (P0441) which I successfully fixed by swapping out the canister purge valve. Since then I hadn't had any trouble until these three codes showed up at once a few days ago. It then dawned on me that the while filling up the truck with gas the last few times, the pump repeatedly shuts off as if the tank is full (when it's not). I think this may be the catalyst for the codes as I had previously smoke tested the system when I was trying to figure out the P0441 code and saw no leaks, and all the lines are pretty new. Therefore I don't think there's actually a leak, I think it has something to do with the mechanism that is causing the fuel pump to shut off while filling.

Hoping to get some guidance if anyone has any ideas on how to fix this. Thanks in advance.

awg

check the archives, but i believe there is a long rubber line between charcoal canister and tank, it gets old (if its original), replace it

check the FSM and/or Parts Manual, which is sure to be illuminating

Very Red XJ

The tube running from the breather on the fuel pump down the driver's side frame rail to the engine is made from plastic not rated for gas fumes. Over time, it gets brittle and cracks or breaks. -This is the Most likely reason for the code. Look carefully along the entire tube - If you are lucky, you will see it. If not, a smoke test will tell you where the leak is. You can splice in fuel line to repair it Or Better - replace the entire line

joshglass

Thanks for the response. Not much rust on any of the lines and I previously smoke tested the system when I was trying to figure out the code that popped up a few months ago that I've since fixed, and didn't see any leaks. Going to double check the line that you mentioned but assuming it looks good, my hunch is that it's the charcoal canister itself based on what I've read.

joshglass

Also, why would a hole/crack in that tube cause the gas pump to stop repeatedly before the tank is actually full? Is it just because there's a loss of suction since it's no longer a fully air tight system?