the other day i went to get gas, the next morning on the way to work the check engine light came on..well i have had gas station flunkies put the cap on wrong or not twist it til it clicked before and the light would come on..well i went to check if that was the case and i see that the little metal flap that is about a 1/4 way down the tube is gone..i am assuming broke off while fueling up?? I have yet to take to nissan for a code reading..but they tell me that that is more just to keep dirt out..but diddnt really give me a definitive answer..i know i gotta go to nissan but just trying to rule out any theories..thanks in advance

 

im not sure what year you have but 02-03 you can get the code yourself. not sure about the flap giving codes or not maybe it could block something just not sure but the code will give you a better idea of whats going. autozone will hook up to your car and tell you the codes free......

 

It was probably a case of the gas cap not being tightened all the way. Try tightening it a couple of clicks and drive it for a while. After a couple of times out, the light should go off.

As far as the flap missing, I'd eventually take out my fuel pump (from the back seat) and try to find it on the off chance that it might screw up either the filter or the fuel pump itself.

 

I don't think the 5th gens have that flap in the filler. I remenber reading about that a while ago but didn't pay it much attention.

I just checked mo wifes 00 and my 02 and neither of them have a flap in the filler.

Running the car with the cap off or not on right can definately throw a code on most cars.

Like ryanmc said, Autozone or just about any parts store will pull and reset the codes for free.