5 Reasons Your Check Engine Light Might Be On

There’s nothing quite as unsettling as driving down the road, minding your own business, and suddenly spotting that dreaded orange glow on your dashboard—the check engine light. Is it a minor glitch or the sign of a serious problem? That little light can spark a lot of anxiety, especially if you’re unsure what it means or what to do about it.

At Discount Tire & Auto in Kamloops, BC, we see this all the time. The truth is, a check engine light can mean a variety of things. Some are simple fixes. Others? Not so much. But one thing’s for sure—you shouldn’t ignore it. Getting ahead of the issue with engine inspection and engine diagnostics can save you time, money, and stress down the road.

Let’s take a closer look at five of the most common reasons your check engine light might be on—and what to do if it happens to you.

1. Loose or Faulty Gas Cap

Yes, really. Sometimes the culprit is as simple as your gas cap not being tightened properly after your last fuel stop. When the gas cap is loose, cracked, or missing altogether, it can cause a drop in fuel pressure, allowing fuel vapors to leak out. This not only affects your gas mileage but also triggers your vehicle’s emissions system, which lights up your check engine warning.

What to do:
Check the gas cap. Remove it, make sure the seal isn’t cracked or damaged, then screw it back on tightly until you hear a few clicks. Drive for a bit—if the issue was the cap, the light may turn off on its own after a few cycles. If not, it’s time for a quick engine diagnostics check.

2. Failing Oxygen Sensor

Your car’s oxygen sensors monitor how much unburned oxygen is in the exhaust as it leaves the engine. These sensors play a key role in your engine’s fuel-to-air mixture and emissions. Over time, they can wear out, especially in older vehicles.

A bad oxygen sensor can cause your engine to run less efficiently, burn more fuel, and emit more pollutants. It might even damage your catalytic converter if left unchecked.

Signs to watch for:

• Poor fuel economy
  
• Rough idling or engine hesitation
  
• Emissions test failure
  

What to do:
Don’t ignore this one. Replacing a faulty oxygen sensor is a fairly straightforward fix, but postponing it can lead to more expensive repairs. Book an engine inspection at a reliable shop like Discount Tire & Auto to confirm the issue and get it resolved quickly.

3. Worn Spark Plugs or Ignition Coils

Spark plugs ignite the air-fuel mixture in your engine’s cylinders. Ignition coils amplify the battery’s voltage to make that spark possible. Together, they ensure your engine runs smoothly and efficiently.

When spark plugs or coils wear out—which happens over time—they can cause misfires. This not only reduces your engine’s performance but also triggers the check engine light.

Common symptoms:

• Trouble starting the engine
  
• Engine shaking or vibrating
  
• Sluggish acceleration
  
• Poor fuel economy
  

What to do:
If your car is showing any of these symptoms, it’s time to bring it in for diagnostics. Worn plugs and coils are a common problem, but they can lead to serious engine damage if ignored. At Discount Tire & Auto, we’ll run detailed engine diagnostics to identify the problem and replace faulty components to keep your vehicle performing at its best.

4. Malfunctioning Mass Airflow Sensor (MAF)

The MAF sensor measures the amount of air entering the engine and sends this information to your car’s computer, which then determines the optimal amount of fuel to inject. When the MAF sensor is faulty or dirty, it can throw off the fuel-air mixture, leading to poor performance, reduced efficiency, and—you guessed it—the check engine light.

Watch for:

• Hesitation or jerking during acceleration
  
• Trouble starting your car
  
• Rough idling
  
• Unusual fuel consumption
  

What to do:
You might be tempted to clean the sensor yourself, but unless you know exactly what you’re doing, it’s best left to the professionals. A quick engine inspection at our Kamloops shop will confirm if the MAF sensor is the problem or if something else is affecting your car’s performance.

5. Catalytic Converter Trouble

The catalytic converter is a vital part of your vehicle’s emissions system. It converts harmful gases into less toxic emissions. When it begins to fail—often due to neglecting other issues like bad oxygen sensors or misfiring spark plugs—it can trigger the check engine light and lead to a drop in performance.

Telltale signs:

• Reduced engine power
  
• Decreased fuel economy
  
• Rotten egg smell from the exhaust
  
• Failed emissions test
  

A failing catalytic converter can quickly become an expensive repair. It also directly affects your car’s ability to operate safely and legally on the road.

What to do:
If your check engine light is accompanied by any of these symptoms, don’t wait. The sooner you get your car looked at, the better. At Discount Tire & Auto, our trained technicians use advanced scan tools to perform in-depth engine diagnostics, catching these issues before they turn into a financial headache.

Why You Should Never Ignore the Check Engine Light

While it’s tempting to dismiss that little orange light—especially if your car seems to be running fine—ignoring it can be a costly mistake. Your vehicle’s onboard diagnostic system is programmed to monitor everything from emissions to performance. That light is your early warning system.

Modern engines are incredibly complex, and a seemingly small issue today can spiral into a much bigger (and more expensive) repair tomorrow. At Discount Tire & Auto, we always recommend coming in for a diagnostic scan as soon as possible. Often, it’s something simple. And if it’s not, we’re here to fix it right the first time—no guesswork, no upsells, just honest, expert service.

What Happens During an Engine Diagnostics Check?

Think of it like a health checkup for your car. When you bring your vehicle to Discount Tire & Auto for engine diagnostics, we connect your vehicle to a high-tech scan tool that communicates with your car’s onboard computer. This tool reads diagnostic trouble codes (DTCs) and points our technicians in the right direction.

From there, our experienced team investigates further—checking sensors, performing visual inspections, and testing components. The result? A precise, efficient repair that gets you back on the road safely.

Your Local Experts in Kamloops

Whether it’s a loose gas cap or a more serious engine concern, Discount Tire & Auto is here to help. We’re not just a tire shop in Kamloops—we’re your go-to destination for reliable, honest, and expert auto repairs. Our seasoned technicians treat your vehicle like it’s their own, and we back everything we do with clear communication and top-tier service.

We handle tire repairs, engine inspections, steering and suspension work, and much more—all under one roof.

So, the next time that check engine light comes on, don’t panic—and definitely don’t put it off.

Let our team at Discount Tire & Auto in Kamloops take a look. Request your appointment online today.