Oh, the dreaded check engine light and all the worries that ensue. Will you make it to work okay? Will your car stall out on the side of the freeway? Will your engine be a smoking hot mess when you pull up in front of school to pick up your kids? Should you even drive?!

At AA Auto Tech, we know how anxiety-inducing a lit check engine indicator can be, but we also know that many times, that light illuminates for a few very simple—and easily fixable—reasons. If your check engine light has you seeing visions of billowing smoke or mid-commute breakdowns, we’re here to help calm your fears. Let’s take a look at the top 4 reasons your check engine light might illuminate, and what you can do to remedy the problem. 


Your Gas Cap is Loose, Missing, or Damaged

When your check engine light illuminates, your first question should always be, “Is my gas cap securely fastened? Before you start worrying, know that sometimes, a simple tightening of the gas cap can fix the issue.

See, the gas cap is responsible for sealing your vehicle’s fuel system and maintaining adequate pressure within the fuel tank. If the cap becomes loose or damaged, it cannot maintain appropriate pressure inside the tank, which affects the engine’s ability to utilize the available fuel. When the engine detects a loss of fuel pressure, it triggers the check engine light to illuminate, which alerts you that there has been a change in pressure.

If your gas cap appears to be securely fastened, the issue may be as simple as minor damage to the part. If the gas cap has sustained damage that allows air to escape or enter the fuel tank, the check engine light will still illuminate. You may need to replace the gas cap to alleviate the problem; otherwise, you’ll end up making more frequent trips to the fuel pump.


It’s Time to Replace Your Spark Plugs

Bad spark plugs are frequent culprits behind check engine light illumination, but fortunately, they’re incredibly easy to replace. Your vehicle’s spark plugs function to ignite the fuel-air mixture within the combustion chamber of your vehicle, but when they wear, they cannot efficiently perform their job. Telltale signs your spark plugs have suffered deterioration or damage include:


●        Worsening fuel economy

●        Reduced engine power

●        Engine misfiring

●        Rough idling

●        Vehicle vibration


Ideally, you should replace your spark plugs at regular intervals according to your vehicle’s factory-recommended maintenance schedule. When you practice by-the-book vehicle maintenance, check engine light illumination can very well become a thing of the past.


Your Vehicle Has a Bad Oxygen Sensor

Your vehicle’s fuel system relies on oxygen to facilitate fuel combustion. For optimal gas mileage and emissions, a specific air-to-fuel ratio is critical. So, to gauge the level of unburned oxygen in the fuel system, your vehicle’s exhaust manifold features a specialized sensor called an oxygen sensor. If this sensor becomes faulty, your exhaust system cannot communicate with the engine to adjust the ratio of fuel and air.

Since burning a “rich” fuel mixture (more fuel, less air) is far safer for the engine than burning a “lean” fuel mixture (more air, less fuel), inevitably, the engine will revert to burning more fuel as a safeguard. If you detect a rotten egg smell or have noticed diminishing gas mileage, these are two hallmark signs of a failing oxygen sensor. You cannot properly diagnose this issue without a code reader, so you’ll need to head to your local auto maintenance shop to have a technician check the engine codes.


You Need a New Catalytic Converter

Your vehicle’s catalytic converter functions to convert poisonous carbon monoxide to carbon dioxide, reducing the environmental emissions your vehicle produces. If the apparatus sustains damage from improper vehicle maintenance or neglect, it will not efficiently convert carbon monoxide, and, unfortunately, your vehicle won’t pass emissions testing.

While emissions testing isn’t currently required in Minnesota, that’s not the only issue that might present itself when your catalytic converter goes bad. Poor gas mileage and higher engine temperatures are also a concern, so if you believe the apparatus is the issue, you’ll need to have your vehicle examined by a qualified auto repair technician.


AA Auto Tech: Comprehensive Auto Repair and Maintenance

At AA Auto Tech, we’re dedicated to providing comprehensive auto repair and maintenance for vehicle owners who reside in and around the Hastings, MN area. Whether you’re looking for factory-recommended auto maintenance, an engine tune-up, or replacement parts, our team has the knowledge and experience you can count on for a job well done. To learn more about our auto maintenance and repair services or to schedule your service appointment, give our team a call at 651-437-2218. Or, you can always feel free to message us on our contact page.