I've been getting an SES code P0455 for a few weeks. I did search and ended up replacing both the purge valve and evap canister and I reset the ECU. Now after about a week the light came back on. I replaced the gas cap first and the only thing I can come up with now is the gas fill spout. You can see in the picture below that it's very, very rusted and I'm wonding if maybe there's a bad seal with that and the gas cap. Is that a possiblitly? I have already spent way too much time and money on this and I'm getting extremely aggrevated. Does anyone else's gas fill spout look like mine, is the rusting common?

 

Anyone know if the rust could cause a bad seal with the gas cap and theoretically throw a P0455 code? Can anyone at least tell me if your gas fill spout is rusted and if this is common with Nissan's? I looked at my Mom's 2001 Buick, my Father's 2001 Town Car, and my Mom's 98 Chevy truck and not one of them had any rust around or on the gas fill spout. But I don't have any Nissan's to compare it too.

 

no rust here. looks like some boob forgot to wipe out the spillage when overfilling the tank. that would eat the paint right off down to the metal, and scraping a filler nozzle sure would help. bam, the exposed metal oxidizes. Wouldn't surprise me. I'd definately try to replace that and as an added precaution, replace your fuel filter. hopefully nothing's gone down in the tank, but never can be too sure.

 

if I remember correctly p0455 is "evap control system, gross leak" Per the service manual this happens when either the gas cap is not on correctly or the evap system is not functioning correctly. If you already replaced the canister and the purge valve, it's probably the gas cap seal. Fix the rust issue and hopefully it will solve your problem...

 

Yes I forgot to mention what P0455 was. Is that rusted part easily replacable? I wouldn't tackle it myself but I was wondering how expensive it would be or if it's even possible to replace it.

 

Before you spend the cash on the purge valve and the canister, try this.

Disconnect the electrical connection that runs to the relay (canister and relay are found behind the drivers side rear wheel). Hit the connection with some contact cleaner. Next take the relay out of the canister, as I recall it takes a 10mm socket to remove the relay. Next grab your favorite can of penetrating spray, I prefer WD-40 and spray the inside of the relay.

Assemble in reverse, but before you put the electrical connection back together use some dielectric grease to prevent additional moisture.

 

I had the same code come up when I ran over some debris and it bounced up into the wheel well (rear driver's side). The debris dented, knocked part of the fuel filler tube loose, and cracked my gas cap. Replaced fuel filler tube & gas cap, problem solved.

 

I would probably look into getting the filler tube segment replaced. That seems to be the most probable cause. The rust isn't allowing the gas cap to properly seal and pressurize the system. The rust is probably cutting the seal on the cap.

 

Anyone know roughly how much that will cost? I'm not going try that repair myself.

 

Double-check your connection at the purge valve. I hate to admit this, but the first time i put it together, I put the plug on upside-down. It'll stay in place and feel like it's plugged in if you push it hard enough.

Another thing to try is to use WD-40 in the connection. WD-40 was originally used as a water-displacement liquid for electrical connections, not a lubricant. It works really well for that.

 

remove the rust form the neck, inspect the seal on the gas cap and replace if necessary.

this is a LEAK code, which means in order for the system to run self diagnosis, the purge and vent valves have to be working properly, so youll be wasting your time screwing with connections and whatnot... if there was a problem there, it'd more than likely throw a fault for that specific component.

theres definately a problem with that filler neck. put a towel in the fill hole to catch most of the crap and remove the rust and if its pitted, polish it as best you can.

 

Sorry for the slow response, I was away for a 5 day weekend. I actually got pissed today and went to the dealer to see if they could look at it and the mechanic basically told me the same thing you said. He said to sand it down good and put some wax on it. I bought a new gas cap and I'm going to do my best to sand it down tomorrow. Do you think I could maybe paint it with some rust oleum? Or would that flake off?

 

it may flake off, it may also create other leak passages. it might be worth a shot, but id try removing the rust and then polishing it first.