I finally gave in and bought a new O2 sensor the other day. Damn car has had the check engine light on for 100K, but just now started getting bad mileage.

I took a look last time I changed the oil - I can see where the O2 sensor is....but I followed the wire and don't see where it disconnects.

Where does it attach to the wire harness?

 

in front of the engine by the top of the radiator

behind the radiator cap in this pic

 

He's got a 3.0 engine.

 

well you probably need to tell us what sensor you are replacing.

you are obviously cali spec

 

i know...doesnt change the location of the O2 sensor wire harness

 

easiest way to figure it out

if you got the sensor from Nissan, the wire cover will be a certain color. match the color of the new sensor to the color of the wires on the car.

 

Never mind!

 

Same holds true for 4th gen harness locations.

 

ive never owned an old @ss 4th gen
but makes sense since its basically the same engine

 

I'll have to pull the code to verify, but I believe its bank 1, sensor 2.

So they go from the exhaust all the way up to the radiator? Are they a real pain to route up there?

 

.. . . . .
.

 

some people shouldnt work on their cars

 

the routing is a pain in the @ss.
like i said, use the wire cover to determine which sensor you are replacing

 

Are you referring to me? Why shouldn't I work on my car?

 

it was a joke

 

locations of all sensors and wire harnesses http://maxima.theowensfamily.com/tsb/NTB02-051a.pdf

 

I really like how your engine cover has been opened up to release heat. Who did it for you?

thanks!

 

a "friend"

 

anyone else getting an eror when loading the link provided by soonerfan? i was able to do it before, nows its screwed up

 

Any idea on the Max if one goes the others are on the way out, so you may as well replace all four? Any opinions?

Thanks

 

If you're not going the sim route, I say replace all four. I did the front two and 3 weeks later a rear went out on me.