Exactly what the title says, Im considering changing all 3 of my o2 sensors. I have a 95 SE with 95k miles. I am the second owener, so i'm not sure if they were ever changed. About 2 months ago I got the cel for my rear heated o2 sensor, but I resetted the ecu and it never came back on. Im wondering what are the advantages of replacing all the sensors with new ones, what will happen (considering that at least one has a problem). Thanks for your input in advance

 

At least change yor rear one. Otherwise you will lose performance and gas mileage b/c car may run rich. At the extreme, could have engine damage if run long enough like that. Just b/c you clear eth computer doesn't mean it went away.

 

So youre saying that the rear one is the most important one? And has the most effect on the car?

 

woah hope that isnt true...mine got broken due to bad placement on carsound cat and havent gotten a new cat or sensor yet, i've been driving without one for a few months...i remember seeing a few months ago in a thread that the rear one was used for diognostic and didnt have a huge effect on the car...need more opinions on this i guess

 

spray the o2 sensor with brake cleaner, should be fine if it only threw one code. If you spray it and it does it again, replace it. The rear one is a lot harder to replace than the front one.

 

Here's a good article on O2 sensors

 

Awesome facts in that page. Pretty much answered all my questions. Thanks again StygianMax!

 

Until I read that, I didn't know a faulty rear O2 sensor can muck up the A/F mixture enough to prematurely degrade the cat. That could get expensive!

 

Yeah well, those little suckers can do some pretty heavy damage. The reason why Ive decided to change teh o2 sensors, other than the fact that my car is 8 years old, is the fact that my idling is horrible, my acceleration is not the way it used to be, im wasting more gas than usual, my car hesitates and jerk (feels like its going to stall), so I figured this woul dbe a good thing to do.

 

Before commiting a lot of money to getting a bunch of new sensors, you may first want to pull them out to clean and see if your car runs smoothly. I've read brake cleaner can be used. Whether it's effective or not depends on how much deposits you've got on the sensor surface.

Just my $0.02.

 

is there any other better places getting O2 sensors than the dealer?
are there any better longer lasting O2 sensors out (i.e. bosch)? and which work better on the max?

-Vadim

 

Just to clarify, the rear heated O2 sensor will not affect your cars performance. It is there to monitor the effectiveness of the main cat only. If the sensor is bad, the only affect will be a CEL. Now the front heated O2 sensors will definately affect your performance as they determine the amount of fuel the injectors deliver. If they go bad, your ECU will revert to a default setting resulting in a rich mixture and as a result, could damage your cats.

 

Thx for the clarification. There certainly are quite a few O2 sensors in Maximas aren't there?

 

Yup, Ill do the brake cleaner idea, better than payin $50 a peice of the o2 sensors, hopefully it will make a HUGE difference.