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

Throttle Body (TBI,inlet manifold control flap)

TBI provides the optimum mixture ratio of air and fuel at all stages of combustion. TBI has immediate response characteristics to constantly changing conditions and allows the engine to run with the leanest possible air / fuel mixture ratio, greatly reducing exhaust gas emissions.

Failure Symptoms
A bad throttle body by reading the error  codes with an OBD II reader. The throttle body can also be examined  for leaks or linkage issues.