Nothing elicits car owner dread quite like seeing the check engine light shining bright on your dashboard. That glowing orange light seems to glare at you, an ambiguous warning that something is amiss under the hood.

Our ASE-certified technicians have diagnosed and resolved check engine light issues on makes and models. As your trusted local auto service experts, we want car owners to feel informed, not intimidated, when vehicle trouble strikes. Here are the most common issues:

Oxygen Sensor Failure

Tasked with monitoring unburnt oxygen levels in the exhaust stream, the oxygen or O2 sensor plays a vital emissions regulation role. Failure of this critical emissions control component can have serious ramifications, causing increased fuel consumption, spark plug fouling, and catalytic converter damage due to improper fuel mixture metering. Replacement of the O2 sensor is required to restore proper engine operation and extinguish the CEL.

Loose, Damaged Fuel Cap

If the fuel system cannot maintain proper pressure due to vapor leaks from a gaping fuel cap, poor engine performance and increased emissions result. Thankfully, an emissions system leak often requires nothing more complex than tightening or replacing a wayward fuel cap to pass emissions testing.

Catalytic Converter Failure

As emissions scrubbers, catalytic converters play an integral role in reducing environmentally harmful exhaust. But failure triggers the Check Engine. Sadly, once a catalytic converter has failed, replacement is essential to pass California smog testing and restore tailpipe emissions compliance. The good news? Proactive maintenance maximizes the lifespan of your converter, minimizing odds of failure.

Ignition System

If the check engine warning shines due to ignition issues like fouled spark plugs or faulty ignition coils, engine misfires and rough running can result. But a relatively minor tune-up consisting of fresh conventional or long-life spark plugs paired with new ignition coils typically rectifies these sorts of ignition issues.

Defective Mass Airflow Sensor

As a critical engine management component, the mass airflow or MAF sensor plays an integral role in regulating and optimizing powerplant efficiency by measuring incoming air volume. Once contaminated or otherwise compromised, a malfunctioning mass airflow sensor cannot provide the engine computer with accurate data. The result is decreased drivability, poor fuel economy and the illumination of the check engine lamp. Our technicians remedy driver MAF sensor issues through professional cleaning or replacement if faults persist.

Troublesome Exhaust Gas Recirculation Valve

Required in most modern engines to reduce tailpipe emissions via exhaust gas metering, the aptly named exhaust gas recirculation or EGR valve occasionally suffers flaws resulting in check engine issues. Sticking open, these valves permit excessive exhaust gases into the intake stream, causing detonation, power loss and rough idle concerns. Conversely an inoperative EGR valve results in increased nitrogen oxide emissions. To clear related check engine alerts, replacement or repair of the EGR hardware is typically needed.

Find Answers and Peace of Mind

While we’ve illuminated some of the most prevalent issues that activate the check engine light, dozens of other glitches can trigger this ambiguous indicator. Without professional diagnosis, determining the root cause can prove difficult, frustrating, and expensive as parts are thrown at potential problems in hopes of resolution.

As your local experts, Precision Auto Care offers car owners accurately diagnosis and efficient repair from our San Mateo shop. Our ASE Master Technicians use state-of-the-art computerized diagnostics to pinpoint the exact cause of your check engine light quickly and reliably, restoring peace of mind behind the wheel. Does your car suffer from a check engine glow? Call us today to schedule an appointment with our diagnostics experts!