Check Engine Light - Five Common Causes
You're driving along minding your own business when all of the sudden a little yellow light pops up on your dash. It's a funny-looking symbol, and it may or may not have the words 'check engine light' displayed. This little light is easy to ignore if your car seems to be running well, but your car is telling you something's wrong, and you ignore that signal at your peril.
Many shops offer free check engine light diagnostics, where the auto technician plugs a small computer into a slot under your dash and a coded message appears. The auto mechanic deciphers the code and lets you know what's wrong with your vehicle. In many cases the light is just signaling that it's time to check, service or replace a certain component. Listed below are five common causes for the check engine light to come on, according to a study done by CarMD.
Faulty Gas Cap
Check this before anything else. If your gas cap is broken, missing or loose, fuel vapors leaking out, throwing your fuel system out of balance. Leaking fuel vapors can reduce fuel efficiency and increase emissions, so check your gas cap to see if its loose or cracked, and tighten or replace it with a new cap from your local auto parts store for just a few bucks.
Faulty Spark Plugs or Wires
Spark plugs seal the combustion chambers and provide the spark that ignites fuel vapors. Like tires, they wear out and fail over time, causing misfiring that can be felt as little jolts in acceleration. Older spark plugs (pre-1996) typically have a lifespan of 25,000 to 30,000 miles, while newer plugs can last as long as 100,000. Spark plugs are fairly inexpensive, and replacement is straightforward.
Faulty Mass Airflow Sensor
This MAS measures the amount of air coming into the engine, communicating with the vehicle's computer to achieve an ideal air-fuel mixture. The sensor can fail over time, party depending on how often the air filter is replaced. A faulty mass airflow sensor will lead to higher emissions, lower gas mileage and more frequent stalling. Replacement sensors are generally a couple hundred dollars, and hiring a mechanic for a little more is a good idea to prevent installation errors.
Faulty Catalytic Converter
The catalytic converter is designed to reduce harmful emissions by converting carbon monoxide and other hazardous gasses into more harmless emissions. Catalytic converters can fail due to faulty oxygen sensors or misfiring spark plugs, and if notice decreased fuel economy or a reduction in acceleration, the catalytic converter may be the cause. Failure leads to a significant increase in the output of dangerous emissions, and since it's especially important in the State of California to keep emissions down to acceptable levels, you'll save money if you take care of this one right away. The cost of a catalytic converter replacement can be upwards of $2,000, so it's very good idea to see what's wrong as soon as the engine light comes on since you may only need spark plugs or an airflow sensor at that time.
Faulty Oxygen Sensor
Your vehicle's oxygen sensors are located in the exhaust system and are designed to measure the amount of unburned oxygen coming out of the tailpipe. This information allows the computer to adjust the air-fuel ratio to achieve an ideal mix, but over time the sensors become covered in burned oil ash and other pollutants, causing them to fail. As a result, your engine begins to run a too rich or too lean air-fuel mix, causing a reduction in gas mileage and increased emissions. If a faulty oxygen sensor goes too long before replacing, you catalytic converter can sustain damage as a result, leading to a much more costly repair. A check engine light diagnostic performed by a qualified and experienced professional will tell you which sensor needs to be replaced to avoid this, and it's usually a very quick fix. Don't put it off!
If your check engine light has just come on, don't delay. In the Covina area, call Hye-Tech Auto at (626) 332-5452 for a FREE check engine light diagnosis.
Hye Tech Auto Blog
Written & Published By MORBiZ
What are the signs of cooling system trouble?
Top Tips for Preparing a Car for a Road Trip
Common Signs of Brake Trouble
Customer Reviews of Hye Tech Auto in Covina
4 Common Reasons the Check Engine Light will Come On
Why Won't My Car Start?
Why are my MPGs Lower?
Identifying Automotive Fluid Leaks
Is it Time for an Engine Rebuild?
Common Symptoms of General Car Trouble
Understanding Your Car's Computers & Sensors
If this Happens, Schedule Engine Repair Now!
3 Signs of a Failed Axle
5 Must Know Signs Your Car Needs Transmission Repair Now
5 Easy Ways to Increase Your Fuel-Efficiency
Does My Car Need Steering Repair?
Scheduled Auto Maintenance You Should Never Skip
Does Your Car Need Auto Electric Repair?
What is Scheduled Auto Maintenance?
Does My Car Need Radiator Repair?
3 Signs it is Time for Clutch Repair
5 Common No Start Problems
Why is the check engine light on?
This Means it is Time for Brake Repair Now
Is it Time for a Tune Up?
Common Signs of Upcoming Engine Failure
Getting a Buyer's Inspection Before Purchasing a Used Car
How do I know if my Car Needs Suspension Repair?
Does My Car Need Transmission Repair? Here's How to Tell
Why Do I Need To Change My Car's Oil?
What Free Auto Services Does Hye Tech Auto Offer
Simple Auto Maintenance for Increased MPGs
5 Types of Signs that Mean it is Time for Auto Repair
Why is Regular Auto Maintenance so Important?
What do these noises mean?
5 Common Symptoms of Cooling System Trouble
Why is the check engine light on?
Excessive Exhaust - What Does it Mean?
5 Symptoms of Brake Failure that You Need to Know
4 Signs You Need a New Starter
Common Issues Requiring Auto Electric Repair
Vehicle Vibes: 4 vibrations that mean your car needs auto repair
How to Find a Great Auto Repair Shop in Covina
3 Signs it's Time for a Wheel Alignment
These 4 Problems Mean it is Time for Engine Repair
What is Routine Auto Maintenance
Why Won't My Car Start?
Warning Signs of a Cracked Engine Block
Strange Vibrations that Indicator Vehicle Problems
Why are Oil Changes so Important?
3 Important Services to Keep your Car Safe
Common Signs of Alternator Trouble
5 Must Know Symptoms of Transmission Trouble
3 Do-It-Yourself Auto Maintenance Tips
Does Your Car Need Radiator Repair?
Why Does My Car Smell Weird? 5 Smells that Mean it is Time for a Repair
Does My Car Need a Fluid Flush?
4 Signs you need Engine Repair
What Does the Suspension Do and Why Should I Repair It?
3 Signs of an Exhaust Leak
4 Tips for Better Gas Mileage this Summer
Three Signs Your Clutch is Wearing Out
What is a Transmission Flush?
Belt & Hose Inspection - How to Check for Damage
How to Know Your Brakes Need Service or Repair
How to Check Your Tire Pressure
Check Engine Light
Five Common Causes