Ok, the check engine light when on first start of August. I then checked the gas cap, and under the engine and didn't find anything unusual. I proceeded for the next two weeks and it stayed on. Mid August I made an appointment for a checkup and then I went away for 2 weeks out of the country. This Tuesday i took the car in at 10 am and by 5 pm I phoned the dealer and they said the car is ready. When I picked it up they said it's the gas cap!? Man it took 7 hours and they didn't call when it was done.

Today, the light went on again. It's under warranty so that is not a big deal. It is an inconvenience however. I will have to call in again and get it checked along with the regular service. Were any of you able to get a loaner car for free?

 

Ok, I took the car in for the second time. This time they kept the car overnight, and I picked it up the next day around 1pm. They said they didn't some diagnostics and adjustment and found that it was a faulty gas cap. The last time they didn't do anything. Anyways I went out of town this weekend and again the light goes on. It will be my third time back? Should I tell the people what exactly to check? The O2 sensor, the Stillen intake, and whatever else?
Starting to sound like an Acura :-)

 

I had the same problem and I always screw my gas cap as hard as I can so thye can't tell me that it wasnt screwed all the way and the light still went on in my 2k2 max. I think that one of the sensors must be faultyl. If it does that again I will call nissan and talk to them.

 

Find someone that can read the codes for you. Anyone with a standard OBD scanner can get them. See what the codes are and go from there. If you get a P0420 code, it's a TSB and your dealer needs to reflash your EEC. Look under the TSB post for the TSB NTB00-070, titled ECM - MIL ON, DTC P0420 SET. I'm having the exact same problem, but the car has 70k on it and I don't feel like arguing. Also, mine ONLY comes on when the gas is under 1/4 of a tank, but I don't think it's related.