Trusted Mechanic for Check Engine Light & Flashing | Gentry Automotive

1. CHECK ENGINE LIGHT JUST TURNED ON? Here’s Exactly What You Should Do For more information visit At: 936-588-4393 www.gentryautomotiverepairs.com 17163 Rabon Chapel Road, Montgomery, TX, United States

2. WHAT IS THE CHECK ENGINE LIGHT? Your check engine light (CEL) is part of your car’s onboard diagnostics system, called OBD-II. It constantly monitors engine performance, fuel combustion, exhaust emissions, and a dozen other things. When something goes wrong (or slightly out of expected range), the system logs a trouble code and turns on the CEL. But here’s the kicker: The light alone tells you nothing. You know something’s off, but not what or how bad.

3. SOLID LIGHT VS FLASHING LIGHT: WHAT IS THE DIFFERENCE? SOLID CHECK ENGINE LIGHT • The issue is likely minor or moderate. • It could be a loose gas cap or a bad sensor. • You can usually drive a bit more, but don’t ignore it. • Schedule a diagnostic soon. FLASHING CHECK ENGINE LIGHT • This is serious. It could mean: misfire, fuel dump, or catalytic converter at risk. • Stop driving immediately. • Towing is cheaper than engine repair.

4. WHAT CAUSES THE CHECK ENGINE LIGHT TO COME ON? 1. Loose or Faulty Gas Cap A loose gas cap can mess with your fuel system pressure and trigger the code P0457. It can also allow fuel vapors to escape, reducing fuel efficiency. Remove the cap and re-tighten it until you hear a click. Replace it if it’s damaged. The light may go off after a few drives. 2. Oxygen Sensor Failure This sensor monitors the air-to-fuel ratio in your exhaust. When it fails, your engine burns more fuel, costing you more money, and emits more pollutants. This means that you’ll get poor mileage, and it can even damage your catalytic converter over time. It is denoted by the codes P0135, P0141. 3. Faulty Spark Plugs or Wires Old or damaged spark plugs and ignition coils can cause the engine to misfire. You may notice rough idling, jerking, or reduced power. These misfires can dump raw fuel into the exhaust and damage the catalytic converter. You need to replace spark plugs and coils.

5. 4. Bad Catalytic Converter • This part filters toxic exhaust gases. When it fails, performance drops, fuel usage spikes, and emissions go wild. Signs include: • Sulfur (rotten egg) smell • Lag when accelerating • Poor fuel economy • Replacement usually costs $800–$2500. It is denoted by the code: P0420 • 5. Mass Airflow Sensor Issues • This sensor controls how much air enters your engine. If it fails, your car may stall, hesitate, or idle roughly. You’ll often get a code and a light flashing on your dashboard.

6. STEP-BY-STEP: WHAT TO DO WHEN THE CHECK ENGINE LIGHT COMES ON • 1. Check the Dashboard • Is the light solid or flashing? If the light is solid, it is less urgent but still needs attention. But if it’s flashing, stop driving. Take your car to a mechanic for a check engine light diagnosis ASAP. • 2. Tighten the Gas Cap • A loose or cracked gas cap can trigger the light because it causes a drop in fuel system pressure. We said it already, and we’ll say it again: twist your gas cap until you hear a click. Then wait. It can take a few drive cycles for the light to go off. If that doesn’t fix it, move to step three. • 3. Check for Obvious Symptoms • Any of these happening? • Car driving differently • Shaking, stalling, or hesitating • Weird noises • Your fuel economy is suddenly getting worse

7. CONTACT US www.gentryautomotiverepairs.com 936-588-4393 17163 Rabon Chapel Road, Montgomery, TX, United States