Ok, my 2000 has started showing the code P0455, vac circuit leak(large). I put on a new gas cap, no change, I have traced every line and hose 3 or 4 times but every time I reset it 10 or so miles later it comes back on. I was told a selonoid could be stuck open. Where are these and how do I check. Thanks in advance for any help!!!!

 

Did you also check the ac system and the exhaust for leaks. Could also be from a bad O2 sensor.

 

ive got the same code and checked the hoses as well....

 

have you guys checked the line to the charcol canister and to the fuel tank it says large that will not be the small lines under the hood

 

An EVAP system leak has nothing to do with the AC system, exhaust or the 02 sensor. It means a fuel vapor leak has been detected. If you cant find the leak by a visual inspection of the evap hoses then the only sure way to find it is a smoke test. Could be the purge valve on the charcoal canister or one of the lines from the gas tank that you can't even see.

 

a week or so before this code popped up, i pulled the jeep over once with a clicking noise....sounded like it was coming from the passenger side back near the firewall.....i actually have a video of it because at the time i thought the bearings in the engine were dying so i was testing that.....(hopefully my soon-to-arrive oil analysis will get rid of that fear)

when i get home from work ill find the video and post it.....but could that be a faulty purge valve/solenoid/whatever?



if that's what caused my problem....could be of some use to the OP (that was my weak attempt to disguise any threadjacking)

 

that where the valve is but i think its clicking because of the leak

 

http://www.teamgrandwagoneer.com/par...iled/2365.html

 

A "smoke test" is a good idea for an evaporative leak that you can't locate.

Find a shop with a smoke machine.

 

I remember someone else had the same issue...turned out to be a problem with the filler neck on the tank....worth a look anyway...

 

Thanks for all the help!!!! I took it and did the "smoke" test and it turned out to be the seal around the fuel pump

 

Good to know! Thanks for the update

 

just curious, what they charge you to do the smoke test?

 

He only carged $75 to find the leak and fix it! Most places I called charge $50 for just the test.

 

Wow!! Thats a pretty good deal! Glad you got it sorted out!