The Service Engine Soon light came on today after 29952 miles on my 2000 Maxima Auto. The car is stock and I'm not sure if it's mandatory to have a 30k mile service. My wife is the one who usually drives the car, but today, it seems like it doesn't like me. Please let me know what to do other than take it to the dealer. I checked all the oil and leakage and there was no sign of problem.

 

How does the car feel? Does it feel like it drives ok? Check the gas cap to make sure it is closed tight. Then I would survey the sensors to make sure they are connected, just in case. If those two things check ok then If you have a scanner use it to get the trouble codes. If you don't have one, go to Autozone and have them scan it. They do it for free. Write down the codes and look them up on the Service Manual. BTW how is your gas mileage. I talked to a service writer and he told me that hes seen quite a few maximas come in for the o2 sensor problem. There is a TSB for that so if it is the O2 sensor problem then it should be covered under the emissions warranty. Good luck.

 

The car drives great. No problem, none that I can hear. But I know nothing of the car, so I'm just gonna go through all the wires and try to see if they are loose. Thanks for the tips. I don't see how the gas cap could lead to the Check Engine Light.

 

Believe it or not, it does. If you drive with the gas cap off or loose it will trigger the check engine light. Having the cap on tight is necessary as part of the emmisions system.

 

The same thing happened to my 2k Max. I took it in and the dealer upgraded the ecu software under the 60k engine warranty. By the way, the code that the obd2 threw was a faulty catalytic converter. Since the cats were fine, it was a signal to upgrade the ECU software.

 

Yes, gas cap is an emissions issue and will throw the light.

Probably what you have is the O2 issue that the EEC needs to be reprogrammed for. I have that issue right now, but I don't want Nissan touching the car, and I'm not going to argue with them to have them fix THEIR problem since my car is out of warranty. I've noticed if the gas drops below a 1/4 tank of gas is the only time the light comes on with that code, but I have no idea how it would be related.

The issue as has been explained to me is when Nissan let the cars out, the legal emissions range expected by the computer was too tight. So they have to reprogram them to allow a larger range. Got me. . .

I've only had it twice in 70k miles and both times is as soon as the gas gauge dropped under 1/4.

 

Mine came on last week in my 2K, (34K miles) and I had never had a problem with my car ever before, and no engine mods. I took it in, and it was just an oxygen sensor. Replaced under warranty, no problem.