01 QX4 Oxygen Sensor replacement

[bryanyoung]

Just wondering if anyone has advice/tips on replacing all 4 O2 sensors on this 01 QX4. I found a nice writeup for a 2000 Pathfinder with the 3.3, but there seems to be more in the way on the 3.5.

It looks like I can get to the upstream sensor on the drivers side easily once I remove the air intake. I don't even know how to get my hand to touch the one on the passenger side.

The 2 downstream sensors are accessible easily enough, but of course the cable attachment points are up near the firewall and look nearly impossible to access.

I've replaced these on my Jeep before, no problem but this Infiniti has a lot more in the way.

I've seen where someone replaced them in less than an hour... If they're accessible, yes, but I don't see how on my QX4.

Thoughts? Tips? Writeups?

[4xq]

For the downstream sensors, I cut the wires and pulled the old wires out, since you really can't reach up far enough to cut the wire ties.

Screw the new downstream sensors in first. Work a coathanger down the back of the engine, and tape the new connector to the coathanger, then work it until you can pull it up into the engine bay. It is a tight fit, but it can be done.

Haven't had to do the passenger side front sensor, so I don't have any great tips there. Is it accessible from underneath?

[bryanyoung]

Yeah.. was hoping since I have the sensors with the snap cable ties to be able to use them, but I might not have a choice.

Don't see a way in from underneath, but I'll look again.

[atraudes]

A word of warning: when I replaced the passenger side downstream sensor, the connector didn't fit (not even close). I went to a few different stores and looked at a few different brands and they all had the same wrong plug. I ended up taking off the old connector and wiring the new sensor into it. No problems since, though! You probably won't run into that problem since I haven't heard anyone else with the same story here, but you've got the same year and model as me so it's worth a mention.

[EntropyQX4]

My rear passenger o2 sensor went out as well.

I did a google search and luckily there is a guide on how to replace it. I followed 4XQ's advice and cut the wires instead of fiddling with the cable ties.

http://perfektadrenalin.blogspot.com/20 ... initi.html