i have a couple three wire 02 sensors (25176708) that are new and been setting around for a while. is there a reason i cant use them on my 93? i have searched and found info on 4 wire ones on a 93 but nothing for the it on three wire. i have found info for the three wire on 3rd gens. i guess the main question is the 3 wire high or low resolution. my 1 wire 02's are fouling so seem to read lean when rich, also dont kick in for quite some time so im thinkin switching may help with that.

 

Your 1-wire sensors use the chassis for a ground. If you simply look at Shoebox's procedure, you will notice that when you install a 4-wire sensor in a 93, you do nothing with the wire on terminal A, since that goes to the (94-97) PCM's "low potential" (= signal ground) terminal, and your 93 PCM doesn't have a signal ground terminal, you can't hook it up. To use the diagram to install a 3-wire sensor, just make believe the wire from pin A doesn't exist, because that is the wire a 3-wire sensor is "missing".

http://shbox.com/1/heatedsensor2.jpg

The only advantage of the heated sensors is the issue of using them on long tube headers, where the sensors become fairly remote from the engine, and do not always stay hot enough to work. If your 1-wire sensors currently work OK, install the 3-wires and only hook up pin B. You don't have to hook up the heater circuit.

 

ok thanks. yah i have lt headers and the corsa exhaust so the flow is good goin by the sensors and they are futher away from motor than stock. still tryin to get the rich idle problem minimized. had these for a car i dont have anymore so i figured worth a try. thanks again.

 

ive had these in for about a month now and it has helped shorten the length of time it takes for the computer to come out of limp mode and the car seems to run better. for anyone with a 93 or earlier that wants to do this with the three wire sensor it has two white wires and one black. the black wire is the 02 sensor wire and the two white wires are for power and ground, does not matter which you run to power or ground. do not ground the black wire or hook the black wire to power except to the 02 wire harness.

 

The computer is not in "limp" mode at any time during normal operation, including cold starts. Limp mode is seldom experienced by anyone. That's basically the ECM running with virtually no external input.

On cold start, its simply ignoring the feedback from the O2 sensors, because they aren't working. That's called "open loop".