I am trying to get an O2 sensor for my 1985 635, but something isn't right. The sensor in my vehicle is clearly a single-wire type, but visits to several stores and internet sites say it's supposed to be a 3-wire type. What gives?
I know universal Bosch single-wire go for about $30-$45, but my car doesn't have a 3-wire sensor, which go for $90-$120!!!
Any ideas on what's going on here?!!!

Here is the diagram of a 1985 635csi USA model.

It is a 3 wire o2 sensor. The added wires are a heater to make it control the mixture quicker.

You may have a Euro model converted to use a sensor and catalyst.

http://members.roadfly.com/kcroncarter/bmwetm121.jpg

Later,

god we should all send ron some beer or something...he's hella helpful :buttrock


ron in 08!