Ignition Wires

Carries the spark voltage to the spark plugs. Faulty wires can drain off the voltage to the spark plug and cause misfiring.

Fuel Injector

Injects fuel into the intake manifold. The ECM tells the injector exactly when to inject, and how much to inject, to produce the needed amount of power.

Voltage Regulator

Control's the voltage supplied to the car's electrical system, preventing overcharge, undercharge and damage to electrical components.

Breather Element

Filters out contaminants from the crankcase gases that are being drawn into the intake system through the PVC valve.

Distributor Cap/Rotor

Routes the ignition coil's output voltage to the correct spark plug. A faulty cap or rotor will cause the engine to misfire or refuse to start.

Ignition Coil

Converts the car battery's 12 volts to the thousands of volts needed to fire the spark plugs.

Air Pump Check Valve

One-way valve that prevents hot exhaust gases from recalculating back through the air pump, protecting the air bypass system.

Idle Speed Control Actuator

Adjusts idle speed as dictated by the ECM, to prevent idle fluctuations and keep emissions low.

Ported Vacuum Switch

Senses engine temperature, and opens or closes vacuum lines to various emissions-related components.

EGR Valve Position Sensor

Detects the opening of the EGR valve, so the ECM can make adjustments to optimize performance.

Crankshaft or Camshaft
Position Sensor / CPS

Monitors the rotation of the engine and tells the computer exactly when to trigger the fuel injectors or the ignition spark.

Air Cleaner Temperature Sensor

Prevents cold outside air from entering the air intake until the engine warms up. This limits emissions and improves cold-engine performance.

MAP Sensor / BAP Sensor

Reads changes in the barometric (air) pressure. The ECM uses this information to adjust timing advance and air/fuel ratio.

Oxygen Sensor / EGO Sensor

Measures the percentage of oxygen in the exhaust, and tells the computer whether the fuel/air mixture is too lean or too rich.

Mass Air Flow Sensor / MAF Sensor

Measures the amount of air drawn through the engine's air intake, so the computer can compensate for altitude and temperature.

Detonation Sensor / Knock Sensor

Listens for engine "ping" so the ECM can retard the spark timing and thereby reduce emissions and overheating, if the engine is knocking.

Coolant Temperature Sensor

Measures the temperature in the cooling system, so the ECM can make adjustments based on the engine's operating temperature. Can also control the dashboard warning light.

EGR Valve

Recalculates a measured amount of exhaust gas into the engine's air intake, to lower combustion temperatures and reduce emissions, especially NOx.

Throttle Position Sensor

Monitors the position of the accelerator pedal and the throttle linkage, so the ECM can make accurate air/fuel mixture adjustments.

Control Module/Igniter

Regulates and times the spark signal to the ignition coil for correct ignition without misfiring.

Fuel Pump

Feeds fuel from the gas tank to the carburetor or fuel injection system. Most fuel injected cars have electric fuel pumps.

Positive Crankcase Ventilation Valve/PCV Valve

Recalculates partially-burned gases from the crankcase to the combustion chamber, to improve economy and reduce emissions while preventing buildup of   sludge and corrosion.

Mixture Control Solenoid

Used on computer controlled carburetors. Controls the blend of air and fuel to produce the needed amount of power and minimize emissions.