1. Faulty Mass Airflow Sensor

Ever feel like your engine’s struggling to breathe? That’s your mass airflow (MAF) sensor, responsible for measuring the air entering the engine to balance fuel mix. In models like the 2012-2016 Honda Accord and Toyota RAV4, the MAF sensor often trips the check engine light when dust or dirt builds up.

Problem: A dirty or failing MAF sensor throws off your air-fuel balance, leading to stalling, sluggish acceleration, and decreased fuel efficiency. It’s a small part with a big job—and when it’s off, your engine’s performance goes downhill fast.

Solution: Our team cleans or replaces the MAF sensor, restoring proper airflow and fuel mix. With diagnostic tools, we get precise readings to catch this issue early and keep your Honda or Toyota running like new.

2. Damaged Catalytic Converter

The catalytic converter turns nasty gases into less harmful emissions, but in vehicles like the 2010-2015 BMW 5 Series and Audi A6, this part often clogs or breaks down, throwing the check engine light.

Problem: Clogged converters don’t just impact emissions—they choke your engine. Imagine your exhaust fighting through a blocked pipe. Power drops. Fuel efficiency plummets. Worse yet, your engine could overheat, leading to costly repairs.

Solution: Sometimes a cleaning will do the trick. If not, we replace the catalytic converter with high-quality OEM parts, giving your exhaust system the smooth flow it needs. At M & R Auto, we ensure every fix meets emission standards, keeping you and your engine safe.

3. Oxygen Sensor Issues

Your oxygen sensor might be small, but it’s essential. Vehicles like the 2011-2016 Ford Escape and Nissan Altima often run into oxygen sensor problems, especially after 100,000 miles.

Problem: This sensor monitors oxygen levels in the exhaust to optimize fuel combustion. A faulty sensor causes your engine to burn too much or too little fuel, which hits your pocket with high gas costs and pushes emissions up.

Solution: We’ll test and replace worn oxygen sensors to keep your engine fuel-efficient. At M & R Auto, our team dives into data readings to ensure your Ford or Nissan breathes easy, performs well, and keeps emissions low.

4. EGR Valve Blockage

The EGR (Exhaust Gas Recirculation) valve plays a vital role in reducing emissions, but in trucks like the 2011-2017 Ford F-150 and Chevy Silverado, carbon build-up can cause this valve to fail, turning on that dreaded check engine light.

Problem: When the EGR valve clogs, exhaust gases can’t recirculate properly. That leads to rough idling, stalling, and a drop in engine power. And with emissions regulations, an unchecked EGR problem could mean a failed smog test.

Solution: Cleaning or replacing the EGR valve does wonders. We remove carbon deposits, ensuring exhaust gases flow as they should. At M & R Auto, we’re ready with the tools and expertise to tackle even the most stubborn EGR issues, giving your Ford or Chevy truck the power to perform.

5. Faulty Ignition Coils and Spark Plugs

Audi and Volkswagen models, especially the 2010-2015 A4 and Jetta, are prone to ignition coil and spark plug issues. When these parts fail, your check engine light blinks to warn you.

Problem: Ignition coils and spark plugs are the spark behind combustion. When one goes out, misfires follow, leading to rough driving, poor gas mileage, and potential engine damage if left unresolved.

Solution: Our shop replaces faulty coils and spark plugs with premium replacements that meet your Audi or VW’s specifications. This quick fix restores your engine’s power and efficiency, helping you drive with confidence.

6. Loose or Cracked Fuel Cap

It sounds too simple, but a loose or cracked fuel cap can cause a check engine light. We see it often in models like the 2012-2016 Toyota Corolla and Honda CR-V.

Problem: A faulty fuel cap lets fuel vapor escape, affecting system pressure and emissions. For newer vehicles that are emissions-sensitive, even a slight pressure change trips the light.

Solution: Tightening the cap is often all you need, but when that’s not enough, we replace it. Our team at M & R Auto stocks OEM fuel caps for a quick and easy solution that restores system integrity and keeps your emissions in check.

7. Transmission Control Module (TCM) Failure

The TCM is like your transmission’s brain, managing gear shifts and performance. In vehicles like the 2012-2017 Chevrolet Malibu and Ford Fusion, a faulty TCM is a common cause of check engine lights.

Problem: A failing TCM leads to erratic shifting, poor acceleration, and even transmission overheating. Imagine a system struggling to find the right gear—that’s what a bad TCM feels like.

Solution: We diagnose the TCM using advanced equipment, analyzing data to pinpoint the issue. If needed, we replace the module and recalibrate it to sync with your vehicle’s system. Our Menlo Park team knows how to get your Chevrolet or Ford back in gear, so you can drive smoothly without transmission trouble.

When your check engine light comes on, it’s more than a warning—it’s a call to action. Each repair we do here at M & R Auto is about making sure your car runs its best. From Menlo Park to nearby cities like Fremont and Palo Alto, we’ve got you covered with diagnostics, expert repairs, and top-quality parts. Got a check engine light issue? Stop by M & R Auto today—let’s get that light off and your car back on track.