The oxygen sensor measures the amount of oxygen in the exhaust gas and sends this information to the engine's computer, which then adjusts the air-fuel mixture to maintain optimal combustion.

An OBD-II scanner is a diagnostic tool that is used to retrieve trouble codes from a vehicle's computer. These codes can then be used to identify and troubleshoot problems with the vehicle's engine, transmission, and other systems.

The fuel injector is responsible for delivering fuel to the engine's cylinders. It does this by spraying a fine mist of fuel into the intake manifold, where it is mixed with air and then drawn into the cylinders.

The catalytic converter is a device that reduces harmful emissions from a vehicle's exhaust system. It does this by converting pollutants such as carbon monoxide, hydrocarbons, and nitrogen oxides into less harmful substances.

The spark plug is responsible for generating an electrical spark that ignites the air-fuel mixture in the engine's cylinders. This spark is created when high voltage electricity flows from the ignition coil through the spark plug wire and into the spark plug.

The timing belt or timing chain is responsible for synchronizing the movement of the crankshaft and camshaft. This is essential for ensuring that the valves open and close at the correct time in relation to the piston movement.

The fuel filter is responsible for removing impurities from the fuel. These impurities can include dirt, rust, and water. The fuel filter helps to protect the fuel injector and other components of the fuel system from damage.

The mass air flow sensor measures the amount of air entering the engine. This information is then used by the engine's computer to adjust the air-fuel mixture to maintain optimal combustion.

The crankshaft position sensor detects the position of the crankshaft. This information is then used by the engine's computer to control the timing of the spark plugs and fuel injectors.

The camshaft position sensor detects the position of the camshaft. This information is then used by the engine's computer to control the timing of the valves.

The throttle position sensor measures the position of the throttle plate. This information is then used by the engine's computer to adjust the air-fuel mixture and control the engine's idle speed.

The MAP sensor measures the intake manifold pressure. This information is then used by the engine's computer to adjust the air-fuel mixture and control the engine's idle speed.

The EGR valve recirculates exhaust gas back into the engine. This helps to reduce emissions by lowering the combustion temperature and reducing the formation of nitrogen oxides.

The PCV valve controls the flow of crankcase gases back into the engine. This helps to reduce emissions and improve engine performance.

The knock sensor detects engine knock. This information is then used by the engine's computer to adjust the ignition timing and prevent damage to the engine.