I just purchased a 2000 Nissan Maxima GXE with 219,000 miles. I’ve had it less than two weeks, and the Service Engine Soon light just came on. I live somewhere that requires emissions testing in order to register the vehicle. My temporary plate will expire soon, so I need to get the car to pass emissions.
This is my first Japanese car and first non-American vehicle. I didn’t know until after I had given the check to the guy selling the car that he used premium gas. He said that Nissan recommends it. I’ve never driven a car that required premium gas before and wasn’t keen on the idea since here, it is 40¢ a gallon more expensive than regular unleaded.
I spoke with my landlord about it, as he is a certified Honda mechanic. He told me to first try getting half a tank of regular unleaded and putting it in with some fuel injector cleaner. He said if I didn’t notice any decrease in performance or knocks, to then just add a bottle of of fuel injector cleaner to every other tank of gas.
I got a half tank of regular unleaded with a bottle of fuel injector cleaner and didn’t have any issues. I then filled the tank with regular without any fuel injector cleaner. I used about ¾ of that tank when the service engine soon light came on. I took the car to Valvoline to get the codes read, and while they couldn’t give me any code numbers, they said it was something to do with emissions.
Here are my questions:
Is it possible the light came on because I switched from premium to regular unleaded or perhaps because I would need to add fuel injector cleaner to every tank of gas I get and not every other tank as my landlord said he does with his car?
Should I try either adding fuel injector cleaner to every tank of gas or just switch back to premium?
If I try either of those, and one of those was the problem, how long would it take for the Service Engine Soon light to turn off? The local Nissan dealerships charge about $100 for a diagnostic, which I can’t afford at the moment.
What exactly does your owner’s manual say about using premium gas? Is it recommended or required?
It would be very helpful to have the actual codes. Most auto parts stores will read them for free, so check with one of them.
I hate to say this, but if you bought a 16-year-old car with 219,000 miles and you don’t have $100 for repairs, you’ve put yourself in a bad spot. A car this old is almost certainly going to need ongoing repairs to keep it running.
Take your Nissan to a large auto parts store and have the codes read and then post them here. Post them exactly as you get them. Someone here may be able to point you in the right direction. Changing fuel grades should not set off a service soon light.
Most parts stores, AutoZone, Advance etc will read the codes for free (except in California) Post them here the # will be something like P0123. I am curious why Valvoline would not or could not give you the number. You did buy a 15 year old car with 200K miles on it, it will need work.
Ref the gas, this is from their manual. You can use regular, but premium is recommended.
Unleaded premium gasoline with an octane
rating of at least 91 AKI (Anti-Knock Index)
number (Research octane number 96)
If unleaded premium gasoline is not available,
unleaded regular gasoline with an
octane rating of at least 87 AKI (Research
octane number 91) can be used.
However, for maximum vehicle performance,
the use of unleaded premium gasoline
is recommended.
The manual also says on page 9-3 that using lower octane fuel can Cause problems with the emissions control system. That could cause check engine lights.
I spoke with my landlord about it, as he is a certified Honda mechanic. He told me to first try getting half a tank of regular unleaded and putting it in with some fuel injector cleaner. He said if I didn't notice any decrease in performance or knocks, to then just add a bottle of of fuel injector cleaner to every other tank of gas.
I got a half tank of regular unleaded with a bottle of fuel injector cleaner and didn’t have any issues. I then filled the tank with regular without any fuel injector cleaner. I used about ¾ of that tank when the service engine soon light came on. I took the car to Valvoline to get the codes read, and while they couldn’t give me any code numbers, they said it was something to do with emissions.
It seems that neither your landlord or the people at Valvoline are really mechanics. No mechanic I know would suggest what your landlord did, but not scan for codes, when it’s obvious that they are there. Maybe he just didn’t feel like getting his scanner out.
And Valvoline won’t tell you the codes? Just doesn’t sound right.
Adding some fuel injector cleaner a couple times over 3 or 4 tanks won’t cause any harm, and could in fact clean up the injectors nicely. But it isn’t something that will help even more by continuing to do it. You only need to do that occasionally, like once every couple of years. On my 20+ year old Corolla I’ve only had to do it once. It’s like washing your hands. Once they are clean it doesn’t help to clean them again.
As posted above, what you really need to do to have any chance to get this addressed is post the diagnostic codes here. Those DTC’s are put there by the engine computer software for this very purpose, and are most helpful towards getting to the bottom of problems like this. Tinkering here and there won’t work. This code method is really the only way to do it with modern cars engines which are nothing if not a massive maze of computers, wiring, sensors, and actuators.
If you simply can’t afford to have a shop read the codes and have no other way to have them read for you, your best bet is to use premium gas for a couple months and cross your fingers, see if the CEL turns off. It’s possible it will, as the regular gas might be causing the engine to pre-detonate and ping. And no more fuel injector cleaner.
And as mentioned by some of the posts above, this particular car is probably not the best choice for you. Based on what you say, you’d serve yourself and your bank account best going forward by coming up with a way to trade to something less of a performance car, and with less than 150K miles on the clock.