My 03 coupe has a P0455 code for large evap leak. I want to test my evap vent valve. I'm trying to take it off. I know this should be an easy job by just taking off the cover on the passenger rear bottom side of the car. Then taking off a hose from the valve and unclip the sensor and just spin counter clock wise and it's done easy peazy. The spinning part is a problem.. I have a coupe and I guess it is easier for the sedans. Because on the coupe you cannot spin it counter clockwise there is a big metal part in the way and it just runs into it. I cannot unlock it because it wont turn all the way enough to take it off. So I was trying to drop down the whole canister just to be able to spin off the valve. But I couldn't figure out how to take the dam canister off. I took off one plastic cover and one metal cover. I only found one bolt that seemed to hold the canister. It wiggled but it wouldn't come down. Does anyone know how to drop it down?

 

Hey bud. Did you check your gas cap first. A loose fuel cap will set off that code as well. GL

 

Yeah I took it off refueled and put it back on and reset the code. It came right back. This gas cap is only a little over a year old. I had bought a new one when I bought the car.

 

EVAP system leaks can be a royal PITA to troubleshoot. Check all your hoses in the engine bay to make sure none are cracked or leaking and everything is securely connected where it should be and all the way over the nipple for the fitting. You should be able to test your EVAP purge/vent valve by removing it from the charcoal canister and hooking it up to a 12V power source and listen for the click. Typically these things allow you to blow air through them when they are not powered up and then when you power them, a solenoid clicks and blocks off the air flow, or vice versa.

Basically what I usually do is remove the valve, bring it to the front of the car and take 2 small copper wires and hook 1 up to my positive battery terminal and then take the other end and hook the hot/power lead on the purge valve, and then wire another connection from the battery's ground terminal to the purge valve's negative/ground lead. This should make a click and toggle the flow or non-flow of air through it.

You could have a leak in your fuel filler neck too. This is a common problem on these cars and there was a TSB to cover fixing this when these cars were still under warranty. A smoke test can reveal the source of a leak if you have one in a place like that.

 

i would clear the code first and see if it comes back. if u miss the gas cap and then put it on later the code will still be there.

 

I was going to do that battery and copper wire test on the valve I saw it on YouTube lol. And see if it closes properly or not. But I can't take the dam valve off without dropping the canister. And I couldn't find how to drop it..

 

I had already cleared the code a couple days ago but today I switched out the gas cap with the oem that came with the car. It's because about a year ago I bought one with the little key. To prevent any sugar in my tank lol. But I keep scanning in and the evap monitor hasn't completed. Gotta keep driving it but I'm pretty sure it's going to come back.. So I'm trying to figure out how to drop the canister. The worst part is I need to do a Star Smog check in 2 weeks to renew the registration. The dam code came up about a week ago

 

Showing you had a locking fuel cap.. Does don't normally work...

 

That makes no sense ^. My car came with a broken fuel door lock, so I had to buy one of these to prevent awful things happening to my car from awful people. Nothing wrong with it.

 

Your fuel door is supposed to lock when you lock the doors. The solenoid could be dead and keeping it from locking. Basically what I'm saying is that if your car is working right you shouldn't need to mess around with a locking gas cap.

Any luck tracking down the EVAP problem yet?

 

 

Op get your self a good quality gas cap not a locking one. You will be fine.

 

Sorry for the delay. So yeah it turns out it was the gas cap.. Smh it was so simple that I found it hard to believe it was going to be that. I've had evap problem on previous cars and it was never the gas cap. So basically yea I had the locking cap and so I decided to put on the original and reset the code . It passed all monitors and the code never came back. So it was a bad gas cap . I have this kind of cap on all my other cars.. I guess I got a bad one

 

Ok. So this is an old post, but I am bumping it anyway because it describes exactly where I am in this process of replacing my g35 coupe evap vent valve.

I have shield(s) removed and two evap canister bolts off.
I have the access plate around the rear wheel well removed...
the plastic that wraps the canister has the two push pins removed, but is not separated from the canister itself; it does not appear to be holding the canister up in any way...????...I have peeled it back already..it doesn't
seem to be doing anything to hold the canister in.

I can't seem to get the canister to drop down in order to turn the vent valve that 135 degrees ccw it needs to come out.

Q: is there a third bolt holding the canister in? (Maybe around the wheel well).
or
Q: does the canister slide or hammer out somehow?
Or
Q: does the plastic shield around the canister hold the canister in somehow?

I know some have removed and relocated these canisters; so maybe some of your remember all this crap.

nobody actually answered the OP's original Question.

thanks.

 

Ok...figured it out.
After removing metal shields..both bottom shields and one in the wheel well.....there is a bolt in the passengers side wheel well...pointing up...13mm..All other bolts are 10mm.

Then the canister does slide out from a hanger and toward the outside fender.