Thermostat Housing
Engine Valve Cove
Intake Manifold
Expansion Tanks
Variable Valve Timing (VVT)
EGR Valve
Secondary Air Pump
Oil Cooler
Blower Resistor
Heater Valve
Throttle Body
Ignition Coil
Nitrogen Oxygen Sensor
Headlight Leveling Sensor
Oxygen Sensor
Temperature Sensor
Brake Light Switch
Fuel Pressure Regulator
Mass Air Flow Sensor
Oil Pressure Switch
ABS Sensor
Auxlliary Water Pump

EGR Valve (exhaust gas recycle valve,exhaust gas recirculation valve)

Meters exhaust gas into the intake manifold. This exhaust gas reduces combustion chamber temperatures and as a result reduces N0X emissions.