Oxygen sensor retrofit help

[EvoStevo]

So I thought I knew what I was doing with this, but after reading a few threads I'm not so sure. I bought a Mustang O2 sensor (part #13953) to adapt for my '89 325is. The new sensor has three wires, two white and one black, while the old one has two white, one black and one gray. I've read that you need to splice the wires of the new sensor into the OEM connector, but I'm not sure what that involves. Does the connector come off somehow? I thought I was just going to be soldering wires together, but I guess that's not the case. Any help is greatly appreciated. Thanks.

Here are some pictures for reference. In both pics, the old sensor is on the left and the new one is on the right:

[EvoStevo]

OK, so after a little more research on google it looks like I'll be doing something like this:


So I'm guessing white goes to white (hopefully it doesn't matter which one is which) and black goes to black, but how do I ground the gray wire? Thanks again.

[EvoStevo]

Bump. Anyone know?

[jlevie]

The simple solution to this is to just get the correct OE sensor. But if you aren't going to do that, at least get the same Bosch part. Which will be a four wire sensor.

[Quailane]

Play with a multimeter and maybe that will give you an idea.

[EvoStevo]

I think I'm going to go with jlevie's suggestion and just exchange this one for a 4-wire sensor. I was misinformed by another thread that lead me to believe this one was the best way to go. I've since talked to my former coworker at Autozone and he says he'll let me exchange it.

[nando]

you need a 4 wire sensor for any car with motronic 1.1 or 1.3

the extra wire is for the heater circuit. Don't use a 3 wire sensor in a car designed for a 4 wire sensor.

[EvoStevo]

So I exchanged it for a 4-wire (part #13275), measured the wire length, cut and crimped the old connector to the new sensor but when I plugged it in it seemed to make no difference. The exhaust fumes still smell like gas. I didn't get any check light with it installed, but then again I don't get one even when it's unplugged. How can I test to see if it's working?

[EvoStevo]

OK, what would be the harm in just soldering the wires together? I've read that you're not supposed to solder an O2 sensor for various reasons, but this whole crimping deal just doesn't feel right.

[nando]

you can solder them, but it's really hard to do so. the wires are stainless steel so the solder doesn't really stick to them.

certain you got the wires right?

[///M42 sport]

heres the official writeup by bosch on splicing sensor wires

http://www.boschautoparts.com/NR/rdonlyres/3BB8A8FA-C707-4333-9098-727C01AF4B7D/0/OxygenSensorInstall.pdf

Heres how I did mine about 5 months ago. Works fine

http://m42club.com/forums/showthread.php?t=8298