OK guys o2 sensor again!

Ok here we go.

Can anybody please tell me if your O2 sensor is goe's will the Check Engine light always come on and stay on. I'm asking cause i think mine went before i brought the car, but it never showed up on Nissan's diagnos. unit when plugged in. It has always run sluggish and when we got it it had bad fuel milage. I'm asking cause i am going to buy another O2 sensor but i dont quite have the funds at the moment and have other priorities to spend the money on first, but if it is the O2 then i want to buy a new one soon as poss.

Thanks and any help would be appreciated!
Shane

try to take out the 02sensor and clean it.
run dia. again and see what happens

what do i clean it with and how? I pulled it out and dont know what i should be touching or not.

Ok i pulled it out and cleaned it with carbuetta cleaner and then put it back in. I didn't diagnos. it but i went for a drive. Not much difference but it was a lot smoother in the lower revs. It took less throtle to take off and at the lower revs the car did feel "lighter" as so many have said. My question now is does anyone still think i need to get a new O2 sensor. Keep in mind that it has done just over 100 000 km or 60 000 miles and is a p11.

Your input is much appreciated!:)

humm....if the o2 sensor isnt functioning correctly ie: not reaching max voltage then the service engine light should go on. the fuel/air mixture is incorrect. but if it doesnt come on on your car, then its probably okay. the difference on my car was night and day.