Im replacing both of my front O2 sensors. I checked the stickies and cant find anything on how to replace the O2 sensors. I know where they are at on the y pipe and how to remove them but I dont know where the connectors to the harness are. Can anyone tell me where the connections are at?

 

easy. get an 02 sensor socket, unscrew sensor from pipe follow the line to the connector and disconnect it. installation is reverse.

 

I just did my two upper O2 sensors today. There is a stickie under 4th Gen How to's. It is geared toward 95-96 but from what I can tell, they are the same.

There are two connectors. The first is right behind the radiator. It couldn't be easier to get to. I think it was just right of center. I think my sensors were original and there were three wires going to the connector. Two were white and one was black. You can see them just as they enter the connector, I think. The second connector is at about 11:00 in the engine bay, on the other side of the engine. Its easy to get to also but not as easy as the first. Once I pulled the sensors, I cut the ties and it was very easy to find both connectors.

That's the two upstream sensors. I don't know about the one after the cat.

The furthest forward sensor was tricky to reach. I used a 3/8 ratchet with a long extension and swivel. I also bought an O2 Sensor socket from Advance Auto for $11.00. It was very helpful. It would have been very hard to get in there with a wrench. I also PB Blasted the hell out of the O-2 sensors and let it settle in before I started.

I bought the Bosch sensors from Advance for $78 each. They came with anti-seize lubricant already on them.

Good luck.

 

My engine is showing a 0303 error code. How much trouble is it replacing this O2 sensor?

 

they are SOOOOOOOOOO much easier to remove when your exhaust is still hot!

 

Does anyone know of any more detailed/clearer how-to's on replacing the O2 sensors than what's in the how-to.

The how-to is actually kind of confusing as the directions say to plug the 02 sensors in and then dangle them under the car?? How can you dangle anything that's already plugged in?

 

Hey Wheelie King.....how you doin, my neighbor So the Bosch sensors gave you no CEL? I'm doing a complete exhaust soon due to its rusting away, and I'll replace my O2 sensors then, along with the y-pipe. I'll get that socket as well, good suggestion.

 

Hey medal_god98SE, are you going to be installing a complete exahust yourself, or are you going to have someone do it? I'm gonna need a new one too due to rust. Since we're both in MA, just wondering if you've gotten a quote anywhere?

 

- Spray WD40 (or whatever you use) on the sensor threads and let it sit for a few mins
- Unplug sensor connectors in the engine bay (just blue and red below)

- Take off old sensors
- Apply anti-seize to sensor threads (DO NOT get it on the sensor part, only apply small amount to thread)
- Install the sensor on the y-pipe
- Connect the connector

After I installed my sensors on the y-pipe, I had my cousin lower some string from the top. I tied it loosely to the connector part and had him pull the wire up and connect it (so the wire wouldnt be twisted)

 

Good idea.

 

This is very helpfull great post!! I am about to have to do this process myself. Thanks!

 

Hi roadrunner, sorry about the delay, just saw your post... In response to your question, I got a quote of an oem cat-back from Nissan of $250 for the b-pipe and $200 for the muffler. I'm going to replace myself. My thoughts are a Budget stainless b-pipe and an oem muffler. I might even do a Budget y-pipe too, and I will replace all 3 O2 sensors in the exhaust as well.