Car: 1995 240sx Manual Transmission
ECU Error Code: 33
Built: 4/94 which makes the car OBDI

Error Code 33 is for a front O2 sensor. I have contacted three Advance Auto parts and they all give me a different sensor to use. On their website they have O2 sensors for upstream, downstream, heated and unheated, manual and automatic transmission. Could someone please tell me what sensor I need? I am assuming it is the sensor in the air intake or somewhere near the intake manifold and not the sensor in the exhaust manifold. Anyway, I am assuming it is an upstream sensor. Am I correct? Now it is heated or unheated? Thank you very much for any help! I figured I would come on TR and ask the real professionals.