1. Failing Oxygen Sensor
Tucked into your vehicle’s exhaust pipe there are multiple small oxygen sensors that constantly tests the exhaust system to measure the air-to-fuel ratio. The sensor transmits that data to your vehicle’s computer, which relies on this information to create an ideal air-to-fuel mixture based on the driving conditions. Symptoms of a faulty oxygen sensor aren’t obvious to a lot of motorists, so the check engine light may be the first time you become aware that a problem exists. Fixing a serious maintenance problem like a faulty oxygen sensor can improve your vehicle’s fuel efficiency by as much as 40%, according to the U.S. Department of Energy.
2. Loose or Damaged Gas Cap
The check engine light may be alerting you to a problem with your vehicle’s gas cap. Addressing the issue may be as simple as twisting the gas cap to ensure it’s tight or replacing a missing or damaged gas cap. While it may not seem like a huge problem, a loose, missing, or damaged gas cap will cause fuel vapors to escape and the EVAP system to not function properly. That, in turn, can lead to an illuminated check engine light.
3. Bad Spark Plugs
Spark plugs are small but mighty powerhouses. They generate the electric spark that enables your vehicle’s engine to start. But when spark plugs become worn-out, they can generate problems. If bad spark plugs aren’t replaced, they can trigger ignition problems, fuel waste, or damage to other parts of your vehicle. Worn-out spark plugs also can prevent your car from starting.
If the check engine light is signaling an issue with the spark plugs, it’s best not to put off getting the problem resolved. Otherwise, your vehicle’s issue could be more severe than just a check engine light. Bad spark plug wires can also be to blame for an illuminated check engine light, along with malfunctioning ignition coils. An ignition coil produces the electricity that enables spark plugs to ignite the mixture of fuel and air found in the engine’s combustion chamber.
Schedule an appointment at your local Firestone Complete Auto Care, and one of our auto care professionals can put the spark back in your vehicle.
4. Weak battery
A weak battery may be the culprit behind an illuminated check engine light. When a battery is faulty or isn’t fully charged, it can’t send the proper amount of energy to your vehicle’s computer system. That, in turn, can cause the check engine light to illuminate. Your vehicle’s dashboard may also feature a battery light that comes on when there’s a problem with the battery or alternator.