Hey Chris, from what I understand, there are only 4 kinds of Narrow Band O2 sensors for ALL cars:
1. Simple1 wire O2 sensor. The sensor grounds out through the exhaust. Generally thought to be the most prone to floating ground problems etc, although literally millions of cars (including mine!) run fine with them, it's easy to replace with....
2. Simple 2 wire O2 sensor. One wire is the signal for the computer, and the sensor grounds through the other wire, which usually goes to a common ground connection for most of the other sensors. A nice, simple reliability upgrade for any car with a single O2 sensor. Can be upgraded to....
3. Heater 3 wire O2 sensor. Has a heating element built in to bring up to temp (600* or so) quickly. One wire is for the signal to computer, one wire runs to an ignition source for the element, and they share a ground. A useful upgrade if you have your O2 sensor mounted too far downstream and it cools off at idle. This would force the computer into Open Loop mode, and perhaps make it run funny, as well as affecting emissions.
4. Heated 4 wire O2 sensor. Same as a three wire, but there are separate grounds for the element and the sensor itself.
Basically, all O2 sensors simply generate voltage based on the difference in the amount of O2 outside the exhaust, versus the amount inside the exhaust. The richer you're running (and all O2 is consumed), the greater the difference in % O2 outside the exhaust versus in, so the greater the voltage from the sensor. If you're running lean (with lots of O2 in your exhaust), the difference between exhaust and atmosphere is less, so you have less voltage from the sensor.
The point is - you can use any O2 sensor you want, as long at it bolts in, and since you're making your own exhaust, you can choose common threads for the bung(s) for a common O2 sensor. In fact, you can buy "universal" O2 sensors, where you simply wire in the connector off of your old sensor onto the pigtail on the new one. I rewired an O2 for my Jeep. All of the downstream O2 sensors are missing at the wreckers, because when the cat is removed, the downstream O2s go too! After some research, I found that BOTH locations called for the same "universal" O2 sensor, telling me it was only the pigtail and connector that were different. So, I repinned the connector from an upstream O2 sensor that looked shiny, and plugged it in. A nice $5 solution to an $80 problem!
I'm ready to be told I'm wrong in this case, but here's a link on a universal O2 listed for a 96 Land Rover 4.0. And a great site for part numbers and cross referencing!
http://www.rockauto.com/catalog/moreinfo.php?pk=343801
You can put the O2 from a Hyundai into a Mercedes with no problems if you have a soldering iron.;)
