1. Upstream (pre-catalytic converter) oxygen sensor: This sensor is located in the exhaust manifold, just before the catalytic converter.
2. Downstream (post-catalytic converter) oxygen sensor: This sensor is located in the exhaust pipe, just after the catalytic converter.
3. Bank 2 upstream (pre-catalytic converter) oxygen sensor: This sensor is located in the exhaust manifold, just before the catalytic converter on the passenger side of the engine.
4. Downstream (post-catalytic converter) oxygen sensor: This sensor is located in the exhaust pipe, just after the catalytic converter on the passenger side of the engine.
