Potential Issues When The Check Engine Light Comes On

• Oxygen Sensor Failure: The oxygen sensor measures the amount of unburnt oxygen in the vehicle’s exhaust system and helps manage the air-fuel mixture. A failed sensor can lead to improper fuel combustion and reduced fuel economy.
• Loose or Missing Gas Cap: A loose, damaged, or missing gas cap can allow fuel vapors to escape, reducing fuel efficiency and increasing emissions.
• Catalytic Converter Malfunction: The catalytic converter reduces exhaust gas emissions. Failure of this component typically results in poor performance, reduced fuel efficiency, and increased emissions.
• Mass Airflow Sensor Failure: This sensor measures the amount of air entering the engine and helps control the fuel mixture. Faulty sensors can decrease performance and fuel efficiency.
• Spark Plug/Plug Wire Issues: Worn, fouled, or damaged spark plugs or faulty plug wires can cause misfires, poor fuel efficiency, and reduced performance.
• Ignition Coil Problems: Ignition coils are vital for starting the car. Problems here could result in misfires, poor performance, and a rough idle.
• Thermostat Issues: A failing thermostat can cause overheating issues and potentially lead to serious engine damage.
• Exhaust Gas Recirculation (EGR) Valve Failure: The EGR valve helps reduce nitrogen oxide emissions and prevent the engine from overheating. A malfunctioning EGR valve can lead to reduced performance and engine damage.
• Transmission Issues: Some cars may illuminate the Check Engine light for certain transmission problems, such as erratic shifting or transmission slippage.
• Evaporative Emission System (EVAP) Leak: The EVAP system captures fuel vapor to prevent it from being released into the atmosphere. Leaks or malfunctions in the system can trigger the light.
• Fuel Injector Issues: Faulty fuel injectors can result in poor performance, misfires, and reduced fuel efficiency.
• Vacuum Leak: A vacuum leak in the engine can cause poor idle, stalling, and reduced performance.