Every driver has or will at some point experience the check engine light coming on. When your vehicle’s electronic-control system detects an unrecognizable issue, it illuminates this small light on your dashboard to signal a potential failure in one or several of the engine’s systems.

While it can be alarming and confusing to see this warning indicator, keep in mind that there is a wide array of potential reasons behind it. Introduced to vehicles in the 1980s, the check engine light signals a problem that the vehicle’s intelligent computer system cannot itself correct. In addition to the light you see, this system will also generate a code that can be read by our top-of-the-line software at The Benz Shop in order to accurately diagnose the root of the failure.

When you notice this indicator on your dashboard, it is best to drive with extreme caution and get to our trusted shop as soon as possible. Depending on the severity, a tow may be recommended. If the light is flashing, your vehicle is signaling an issue that could result in immediate failure, and therefore is a danger to you. In this case, a tow is most definitely advisable.

Why is my check engine light on?

When the check engine light appears, the uncertainty of the cause can lead to a pretty stressful response. Here are the most common reasons:

  • Gas Cap: The gas cap plays a far more important role in your vehicle’s smooth functioning than you might think. It acts as a seal, maintaining the correct engine pressure and preventing fuel vapors from escaping. If the gas cap is left compromised for long, you may notice your vehicle riding rough or experience poor fuel efficiency. Once you have tightened the gas cap, the warning light may need a day or so to reset. If it doesn’t reset on it’s own, our trained technicians at the Benz Shop are able to access your vehicle’s internal computer system and do it for you.
  • Catalytic Converter: A compromised catalytic converter is a far greater issue than a loose gas cap. In fact, this is possibly the worst case scenario when the check engine light comes on. The catalytic converter is a crucial part of your vehicle’s emissions system, as it filters the toxic carbon monoxide. If it becomes clogged or damaged, your car will not pass its emissions test. It is also a red flag because when the catalytic converter fails, it is usually as the result of another issue inside the engine.
  • Spark Plugs and Wires: If you are familiar with any kind of motor, you will know that the spark plugs are responsible for providing the initial spark required for combustion. Over time, with natural wear and tear, these plugs will need replacing. It is recommended that you have them replaced every 25,000 miles. If not properly serviced according to your manual’s schedule, the plugs will become faulty and lead your engine to misfire or fail to start.
  • Oxygen Sensor: A certain amount of oxygen escapes the engine unburned. The oxygen sensor in your Mercedes-Benz monitors how much of that oxygen passes through the exhaust. Due to all the debris, fumes, and ash in the exhaust, the oxygen sensor is highly susceptible to getting caked in this dirt, limiting its ability to perform properly. If this is the reason your engine light is illuminated, it will need to be replaced without delay.
  • Mass Airflow Sensor: The Mass Air Flow (MAF) sensor plays a similar role in measuring the amount of air entering the engine, thereby indicating to the vehicle the amount of fuel required. The air-fuel balance is a delicate one, and if the MAF sensor fails, you risk experiencing stalling. The mass airflow sensor allows your car’s computer to know how much fuel is needed based on the amount of air coming into the engine. Faults can decrease efficiency, increase emissions, and cause your car to stall.
  • Exhaust Gas Recirculation Valve Failure: The ERG system serves to limit how much nitrogen oxide escapes your vehicle’s engine. The engine warning light might appear to indicate a compromised EGR valve.
  • Dead Battery: If your battery is low or old, the check engine light may illuminate, signaling that it is time to charge or replace the unit.

The Benz Shop is the Best Choice in Phoenix

When you own a Mercedes-Benz, you want to ensure Mercedes O2 Sensor Check it has the best care possible. At The Benz Shop, we pride ourselves on providing an affordable, personable alternative to expensive dealership services.

Because we focus on only one brand of car, at The Benz Shop, we stay completely up to date on the latest techniques and keep the most state of the art equipment on hand for diagnosing and repairing your Mercedes. Our service technicians have certified extensive Mercedes factory training and luxury motor vehicle training.

We service Scottsdale, Glendale, Tempe, Chandler, Paradise Valley, and Phoenix, Arizona, so call us today at (480) 867-6695 to ensure your Mercedes is in the most capable hands possible.

We will be closed from
January 17th – January 21st
as we move to our new facility located at
5160 W. Phelps Rd. Suite A, Glendale, AZ 85306.

We look forward to serving you at our new location!

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