ON the 90 ls there is a one wire o2 sensor which sits on the headers now On my car I have a 99 ls engine and still using the headers and down pipe from the 99 ls. But the 99 ls piping has the o2 sensor bong after the engine So i'm wondering if the 1 wire o2 sensor is functioning right? I'm not getting a check engine ligth but when I put a volt meter to the wire all I get is 0.05 volts so i'm defenately not getting anything from the 02 sensor so I'm wondering if the sensor is bad or to far away to get heated by the exhaust fumes?