I find this very odd.
I bought a new O2 sensor, proper NTK job, and the website came up with a three wire version. The part number is OZA446-E18. When I look at the car, the current sensor is four wire. According to the NTK catalogue, the 4 wire version didn't appear till April '98. However, there is an empty socket for three wires, but I can't tell what it's for. Is this a red herring?
I've only had the car 12 months and still finding my way around. I've been working on the basis that it's a series one car - it has the early aluminium cover over the plugs. However, the chassis plate states that the tipo is 916/S2. Is this significant??
The VIN is 6026998.
Next silly question - where is the three wire connector for the diagnostics?? If I can hook up my laptop, I may be able to sort it out!
I've now finished replacing the belts, airflow meter, plugs, filters, oil and the O2 sensor, plus installed a strut brace.
Many thanks for any suggestions or clarification.