check engine light

Has this ever happened to you? You’re driving along and all of sudden your check engine light turns on. While a check engine light is no reason to panic (unless of course your car dies in the process), it is an opportunity to call your local mechanic and have your car checked out. If you’re check engine light has recently turned on, and you’ve wondering what it could be – we’ve got 7 things to check (or really have your mechanic check).

Catalytic Converter

Your catalytic converter changes carbon monoxide to carbon dioxide which helps protect the environment. When your check engine light turns on, it could mean that you have a faulty catalytic converter. Signs that your catalytic converter needs some attention are reduced fuel efficiency, decreased engine performance, and an increase in emissions. It’s important to note that replacing it is not always the answer. A faulty catalytic converter is typically caused by something else in your car – for example, a blown head gasket can cause your check engine light to go on. Be sure to have your mechanic check to see what’s really going on below the surface.

MAS Airflow Sensor & the Check Engine Light

Your MAS airflow sensor determines how much fuel is needed to run the engine. It measures the amount of air entering the engine, and can be susceptible to oil and dirt build up. When your MAS airflow sensor needs a cleaning or fails, your air to fuel ratio can get off which can cause failures in other areas of the engine like decreased fuel economy and engine performance.

Oxygen Sensor

Your oxygen sensor measures the amount of unburnt oxygen in your car’s exhaust. This sensor will send data back to your car’s computer which uses that information to regulate the mixture of air and fuel that enters the engine’s cylinders. If your oxygen sensor fails, your car can keep running, but will burn more fuel. If left unaddressed, driving with a faulty oxygen sensor can damage your spark plugs and catalytic converter.

Vacuum System

Your vacuum system helps lower emissions by routing the fumes from evaporated gas through your car’s engine. Your vacuum hoses can crack or dry out when exposed to intense heat or cold. Over time, the elements and wear and tear can cause cracked fittings and loose connections. Ask your mechanic to check your vacuum hoses and fittings if your check engine light has turned on.

Ignition Coils

Your ignition coils deliver electrical pulses to each spark plug. When your engine’s computer sends a signal, the ignition coils will release pent up energy to each spark plug where it ignites the air and fuel mixture. Your ignition coils are prone to failure after several years. Some signs to look for include: decreased engine power, and poor fuel efficiency.

Fuel Injector

Each cylinder in your engine has a fuel injector. They are small, electronically-activated valves that regulate how much fuel is sprayed into a cylinder during the intake cycle. Our gas has impurities and when combined with carbon from the combustion process in the engine, it causes the tiny holes in the injector tip to clog and plug. A completely clogged fuel injector can get stuck in the open position which causes it to continuously leak fuel into the cylinder. This can cause your engine to run roughly so you’ll want to have your mechanic check that out.


Your alternator works with the battery to supply power to your car’s electrical system. If the alternator fails when you’re driving, your radio will go off, your lights will dim, and you will have difficulty driving (your power steering and power brakes won’t work). If this happens, you’ll likely be stranded by the side of the road waiting for a tow

These are only some of the reasons why your check engine light will turn on – to be on the safe side you’ll want to have a mechanic inspect and diagnose what’s underneath that check engine light. If you’ve recently had this experience, our team would love to help. Simply make an appointment and our team will diagnose your issue and get you back to enjoying that summer drive.