Tray replied: "Tune up and clean injectors with spray."

gary o replied: "sounds like the throttle body is dirty. Get a can of special throttle body cleaner and follow the directions on the can. I would do this first."

John Paul replied: "Several things only 600 separate engine and check engine light codes. That light turns on because there is a possibility of excess emissions. Driving a car with a Misfire will cause the cat converter to overheat. Have your car diagnosed by a Nissan Technician or a very good independent shop."

njdevil replied: "Wow odd because I have a 2001 Nissan Altima GXE Limited Edition (hopefully that will change by the end of this week though). I would be very surprised if it is the exact same thing, but I had a similar problem. I am used to the car's fan turning on loudly or it to raise or lower its RPM while stopped for a while, but a couple months back I had a bigger problem. When I was stopped at a light or a stop sign for more than 5-10 seconds the RPM guage would jump up about 500 RPM sporadically. This would continue once every two seconds until I accelerated, at which point it was gone. This happened a few times but it became much much more frequent until it was everytime I stopped. Also it was happening worse and worse over time. What really annoyed me about this problem was that as it was surging up and down the car was kind of lunging with it a bit. If I was reversing out of my driveway it was like I kept tapping hte break or something because the entire car would be lunging with this surge in RPM. Finally I got it checked out and the news was not good. It was a leaky intake valve. The valve was leaking air so when we were stopped it was pumping the air in, but some was escaping causing the car to sputter and lunge and do crazy things. It is VERY IMPORTANT that you get it checked out because if it is the same problem then it could be a catastrophic repair if the valve breaks. To just fix it, it is still not going to be cheap. Expect $800-1000. I hope this is not the issue, but they sound very similar. My 01 altima is having more and more problems (not as huge as this one, only around $500) so I am getting rid of it within a couple of week. It has 95,000 miles on it and it is not doing well at all. My girlfriend has the identical car (by accident not by design) with 47,000 miles on it and it is doing fine (even though the few repairs it needs are big ones). I'm just saying that I wouldnt throw huge amounts of money in the car after a while. Sorry to ramble. If you do get it diagnosed please let me know what it is as I am curious. Even if I dont get best answer if you could add it in. Thanks and best of luck :-)"

Li replied: "www.redrosezone.com, check this,and u will find the answer"