Service Engine Soon light won't go out on a Nissan Quest

We recently bought a 2001 Nissan Quest. The “service engine soon” light was on when we test drove it but the salesman assured us it was a simple fix and would be taken care of.



We have taken the car to this dealer 4 times and they even sent it to a Nissan dealer and the light still came on the first time I drove it.



They have replaced the gas tank sensor, fuel pump, computer and even the gas cap because they thought the pressure wasn’t building up enough to allow the computer to register it.



I’m a little old lady who only drives the car to church, kind of the old is right, and I’m at a loss if they are just pulling me around and this car is in fact a true lemon. Will it be safe to drive with this light on? I’m basically housebound for fear the car will break down on the road. Can anyone help?

With what they have replaced so far, I’m guessing the SES is on because of an evap code. Basically, the evap system is designed to keep gasoline fumes from the fuel system and gas tank from leaking out to the air, as required for emissions. There are sensors that check the evap system for possible leaks, and will set a code if such a situation exists.

This is not a critical problem, and should not cause damage to the engine, or leave you stranded. But, the dealership is obviously aware of and trying to fix this. I suggest you let them continue, and find a solution on their dime. This should have been fixed before it was sold.

Hello, as long as the check engine is not flashing, no immidiate danger to engine will occur, but this hard code as we call it, may hide other SES related problems. A simple thing that you could do is to see for yourself if the lip of the filler neck for the gas tank is not rusted. This is very common in Nissan cars. Replacing the gas cap has no effect if the seal is not flush cuz of the rust on the filler tube. By the way, I believe that the fuel pump was changed for nothing if this was a evap related code. Verify or always ask which code was present at the diagnostic stage of the repair before proceding with replacing parts. Also on these models, there is a canister purge valve that often fails, has this been verified by the dealer. Please come back to me on this. As a auto tech myself, I am tired of mis-diagnosed evap concerns.

If you live in a area that does not require emissions testing (that’s what this light is all about) and you are otherwise happy with the vehicle, just ignore the light and drive the car!

If there is an emissions test in your future, MAKE THE DEALER FIX THE PROBLEM, even though there is no problem…You can not pass an emissions test with that light on…

The vehicle IS safe to drive. If you take the suv to an auto parts store, many of them will read out the code for you. Just ask. Then, bring those codes here for advice.
The dealer’s mechanics haven’t made the repairs because they are incapable, or the Dealer won’t let them. You may have to take that dealer to small claims court for a resolution. There is no excuse for incompetence, or, blocking a repair, if that’s what’s happening.

Anything is fixable. However it would be helpful if we knew what the code or codes have been and are now. They should be in the format of “P0123”