Is your ‘check engine’ light on? Here are 10 possible reasons why - PART 1
Your car can’t talk, but it knows how to communicate to tell you something is wrong. The orange, engine-shaped icon that flashes in the instrument cluster is its way of letting you know it needs attention. Don’t ignore it, and don’t worry if you see it. The list of problems that can trigger the check engine light is long, and seeing it isn’t a guarantee that you’ll need to pay a four-figure repair bill to keep your car on the road. Sometimes, the fix is cheap and simple.
Here are the 10 most common problems that can trigger a check engine light. Keep in mind the fault code that caused the light to turn on in the first place is stored in your car’s onboard computer, and you can retrieve it using the DebugMyCar™ device linked to an app to get a precise idea of what exactly is wrong under the hood.
Oxygen sensor failure
The oxygen sensor (sometimes called an O2 sensor) measures the amount of unburnt oxygen in a car’s exhaust system. It sends data to the vehicle’s computer, which uses it to regulate the mixture of air and fuel that enters the cylinders. An engine will keep running even if an O2 sensor needs to be replaced, but it will burn more fuel than usual. In the long run, a bad O2 sensor can damage components like the spark plugs and the catalytic converter. It may also cause a car to fail an emissions test.
Loose fuel cap
A loose fuel cap is one of the most common reasons why the check engine light turns on. The cap is a crucial part of a car’s fuel delivery system. It notably prevents gasoline fumes from leaving the fuel tank, and it helps keep the whole system under the correct pressure.
Catalytic converter failure
The catalytic converter is integrated into a vehicle’s exhaust system. It turns the carbon monoxide generated during the combustion process into carbon dioxide. It’s a fairly simple part, and its failure can often be prevented. That’s good news, because a new one costs between $200 and $600 depending on the make and model. Every late-model car that runs on gasoline has a catalytic converter.Performing regular maintenance (such as oil changes) on time is key to keeping your car’s catalytic converter in working order.
Spark plug/ignition coil issues
Put simply, an ignition coil generates the electricity the spark plugs need to ignite the fuel and air mixture in the cylinders. Classic cars have a single coil, but many modern vehicles use one coil per cylinder. If your ride has a V8 under the hood, you could have eight separate coils. The monstrous Bugatti Chiron has 16. No matter how many you have though, a malfunctioning coil will almost certainly trigger the check engine light, but remember, if your car burns diesel, you have neither ignition coils nor spark plugs.
Bad spark plug wires
As its name implies, a spark plug wire transfers electricity from the coil to the spark plug. Without it, the fuel and air mixture in the cylinders wouldn’t ignite. The vast majority of cars use a single wire per cylinder, but there are models — notably, some older Mercedes-Benzes — with two spark plugs per cylinder, and consequently two wires.