Thread: Nissan gas cap

Hey dudes I have a question about some Nissan gas caps, The one on my NX I believe is bad since I have noticed the faint smell of gas after running the car around for a while and the idle was kind not very smooth and or rough. Well, I have a couple of caps laying around from various Nissans I have owned and some I picked up at yards. Well I replaced the cap and the smell of gas is gone and the idle believe it or not is smoother but the cap I replaced it with is a 2.0 and the one of the car was a 2.5. I think that is the pressure in PSI that it holds before it cyphers off. I am just wondering is there any difference between these caps and should I order a 2.5 cap from Nissan to replace it or find one in a yard? Just wondering if anyone here knows anything about Nissan gas caps.


they are the same cap one has a E on it the other has a C for whatever that means.

If the shoe fits...

If you have a cap that screws in and has a good gasket I think you should be fine.

Do you still have your charcoal can hooked up? If so check and see if it is full of fluid. If it is get a new one, it's dead.

Have you smelled fuel with the windows up (if this is the case then check the fuel pump gasket?

yeah, the car is 100 percent stock. Nothing was ever done to the car though and it spent a lot of its time above the Mason Dixon time and then went to the deep south. The only thing that saved it from being a rust bucket was the under coating they do on Northern cars everything is coated with that black tar like stuff so it did not rust. Even wheel wells are clean.

I will check the canister, I have already replaced the fuel tank O ring and fuel lines as well as installed a new check valve because this one was humming when you stopped not reliving the pressure. I just happened to have a Nissan OEM gas cap laying around. I think the old cap had a small leak causing gas vapor to escape. I have never smelt gas in the car but when you stepped out of it and walked by the gas tank cap you could smell it. I replaced it and it seems to idle better as well for whatever reason that is.