I've searched the archives but can't find the answer to my dilemma.

I need a precat O2 sensor for my 1999 C50 2.3t. I was under there yesterday and it is a 5 wire sensor.
The local napa store only shows 4 wire units listed for this car. When I look online all I find listed for this model are 4 wire units. Some research has led me to believe that Bosch # 17038 might be the one I'm looking for. Can anyone verify this?

 

Please clarify what kind of car you have. No C50 in 99, no C50 in the states I believe. No C30 in 99. No V50 in 99. Do you mean a C70? And then post in the appropriate thread, I'm sure you'll get an answer faster.