there are 4 sensors. 2 pre cat sensors and 2 post cat sensors.
the pre cat sensors (both) are located in the overhead engine compartment towards the passenger side.
the post cat converter's are located underneath and to the mid section of the engine and a pain to get to.
hope this helps.
The pre-cat O2 sensors are (from standing in front of the engine) to the left of the engine, on the top of the exhaust manifolds. The post-cat O2 sensors are seen from under the vehicle at the end of the exhaust manifolds.
1st o2 senor is between exhaust. 2nd o2 sensor is under shifter
The bank 2 pre cat O2 sensor is in the rear exhaust manifold, the bank2 post cat O2 sensor is under the car after the catalytic converter, P/S nest to transmission.
Remove the vacuum hose from the O2 sensor. Remove the wiring harness. Remove the O2 sensor retaining screws. Reverse the process to install the new O2 sensor.
O2 sensor? Hey its a part and parts wear out. Oil additives or fuel additives can ruin an O2 sensor as well.
See related link which includes instructions for testing any O2 sensor.
The O2 sensor is in the exhaust pipe before the catalytic converter.
The 2000 Mazda Miata O2 sensor bank 1 is located on the firewall in the engine compartment. The sensor can be found on the passenger side of the firewall.
All O2 sensors are screwed into the exhaust system.
The upstream O2 sensor is mounted in the ehxaust manifold The downstream O2 sensor is mounted in the exhaust pipe after the catalytic converter
It is on the passenger side of the engine, right on top of the exhaust manifold.
The upstream O2 sensor is mounted in the ehxaust manifold The downstream O2 sensor is mounted in the exhaust pipe after the catalytic converter