How many oxygen sensors on a 1997 F150?

Answer 1

1996 started the OBDII (On-board Diagnostics Generation 2) era. Most, if not all, OBDII systems measure the degradation of all components associated with emissions controls, which includes the O2 sensor and catalytic converter. To accomplesh this, there are two O2 sensors, one upstream, and one downstream. The upstream is usually located on the exhaust manifold, and the downstream is located just after the catalytic converter/s. The purpose of the downstream is simply to assess the efficiency of the upstream O2 sensor, as well as that of the catalytic converter, to make sure neither has not stopped working. The answer is that there are, most likely two O2 sensors on your car