There are 2. Both are located on the catalytic converter on the left side of the vehicle. One is at the top of the converter the second is below the converter. Both are 4 wire types.
Underneath the alternator
where is the O2 sensor on a 2002 chevy trailblazer
Just underneath where all of the pipes meet on the extractors/headers
The 2002 Chevy Cavalier 02 sensor can be found attached to the air cleaner housing. The O2 sensor will be on the back side of the air cleaner housing.
Click 'Install'...
P0135 O2 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1) Bank one is drivers side. Sensor 1 is the one closest to the engine.
Mitsubishi Galant, 2002, 4-cyl, O2 sensor, bank 1 sensor 1 (upstream)... PART NUMBER: MR506364
Good Chance this is caused by a faulty O2 Sensor. I had the engine light stuck on in my 2002 Montana and replaced rear O2 sensor and it turned it off.
It has both an up and a down stream oxygen sensor.
No, the O2 sensors are out of the "loop" until the engine warms up.
2002 Suzuki gran vitara
There are two in the exhaust on the back side of the engine.