Ok here is the deal. I have had a knock sensor code for quite some time now. I haven't gotten around to replacing it because I am currently getting around 425 - 440 miles a tank. So I get the SES light. I get the codes read. It calls out knock sensor, and both of the front o2 sensors. It has been a bit sluggish and the mileage did suck, like 350 a tank. So i decide to replace the o2 sensors. Yesterday morning when I was about to go to Advanced to get the sensors, i started the car and the CEL light was off. The car was performing like normal. So i thought maybe everything is ok.This morning I go out and the damn light is back on.

Does anyone elses CEL light come on then go out only to come back later?

 

that light is a real *****

 

It happens. I've had an on-again-off-again CEL for a "catalyst inefficiency" for the past 2 months. Just when I'm feeling motivated to go spend a ton of money on a shiny new exhaust, the light goes off again.

 

does it happen when u drive around and it warms up ?
it MAY be happening because the sensors have an operating voltage range. when the car is cold it might be in or out of range and that changes with temperature so the sensors are partially working -- its a long shot theory.

If it happened to me i would probly replace the sensors that its giving the codes for

PS: damn ur getting like 425-440 Mi a tank ? wow thats nice, my personal best is like 350 Mi a tank thats with the KS code right now and all the maintenance kept up.

 

No. The light comes on as soon as I start the car. I doesn't disappear after it has warmed up. That was the first thing I looked for. It just went away this morning. It came back once I came in and typed this thread. I don't know what is going on. I'm gong to go ahead and change the O2 sensors. I will probably go away as soon as I go get the sensors.

Yeah, I have always gotten at least 400 miles to a tank. Another maxima owner thinks that is the craziest thing. I once got 500 to a tank driving to Atlanta. That was with the A/C on and driving 75 mph. I run 93 and keep the maintenance up. I was gonna change the KS but why when I get awesome mileage.

 

oh ok so thats mixed HWy mileage i see, my hwy MPG was 29 when i took the car to niagara falls from Toronto and back going 120 - 140 Km/h with open sunroof and slightly open windows

my city mileage is about 20-21 on average sometimes 19 when i abuse the car and sometimes 22 when i am driving sleepy in the mornings. this is exactly as the car is speced by nissan, i duno maybe the website i am using to calculate this is wrong, i get at least 550 KM on a tank and the light is not even on, i still usually have like half of the last quarter left.