I've got 110k on a '95 LS. Got the infamous "check engine light" recently and dealer replaced right rear O2 sensor. Two months later, another light. Should I bite the bullet and replace remaining three O2's or should I pay dealer to diagnose and replace. What is life of O2 sensor? I don't have any emmission requirements so I'm not overly concerned about a few extra hydrocarbons. I can replace all O2 myself for the cost of a dealer visit but light could be something else.

 

Why not just buy an aftermarket O2 sensor? I'm getting ready to replace all my O2 sensors.

This is where I'm probably going to buy from: http://oxygensensors.com/

Check out their FAQ section, good info.

 

I just finished replacing my O2's in a 97 LS. Not a big job, but not a cake walk.

I used a 5/8 box end wrench to remove them. They are pretty tight in place so it took some work to get them free.

Probably took a couple of hours to do with figuring out routing, wrench size, cleanup, etc.

The connector for the front sensors is located under the carpet on the driver/passenger floor board. Someone wrote up a great step by step on changing them, in the LS400 forum I think or it might be in this forum.

I'd stick with OEM sensors. The aftermarket require cut and splice of the wires to splice in the old connector to the new sensor.

Take your car to AutoZone and have them check the error code and diagnose if it's the sensors.

 

I tend to agree with additude--you're already saving some money by electing to do it yourself, so stick with the oem sensors and you know you won't have any problems with the fit.

I don't yet have any factory manuals, otherwise I'd check for you, but perhaps someone knows whether it's possible for the DIY to diagnose/read the trouble codes. This might be wise to do before you buy anything...

As for the useful life of O2 sensors, I've heard anywhere from 60k to the life of the car. As with most anything, the truth i suspect is somewhere in between. Personally, I've had to replace them at over 130K on two Hondas that I own. The first one I bought was Bosch from AutoZone, the second I bought original Honda part for about $100 more...entirely subjective, but I 'feel' better using the factory part.

Mike

 

Are these O2 sensors the single wire type?

A cordless soldering iron, some shrink tubing and it could be an in-out deal. If the factory sensor comes with a connector and not generic, I'd probably install the whole deal or fabricate a duplicate connector accessible from the bottom.

Last I spoke with my Toyota service rep, he told me the latest bulletin was to replace the sensor annually but he personally felt every other year was more than acceptable. So roughly every 30K. I dunno what to think.

When one of my Toyota's didn't pass smog, the O2 sensor didn't do a thing and I swapped through 3 different ones ranging from new to factory original with some 100K miles on it. . Plugs looked good and performance/milage was still par. <shrug>

 

I believe the two sensors before the cat are 4 wire, and the ones after are two wire.

 

Figures, anthing to add complexity.