Check engine light on? This is one of the biggest automotive headaches drivers deal with, not necessarily because a check engine light means anything serious but because of the number of different possibilities that could be causing the light to come on. That’s why your best bet is to visit an auto repair shop in Sacramento that specializes in check engine light diagnostics . A mechanic will use advanced diagnostic equipment to pinpoint exactly what’s causing your check engine light to come so you can get back on the road as quickly as possible. In the meantime, here’s a look at some possible causes of a check engine light. 
Faulty Oxygen Sensor
The oxygen sensor measures the amount of unburned oxygen in the vehicle’s exhaust system. A faulty oxygen sensor can cause the engine to burn more fuel than needed, resulting in up to 40% lower fuel economy. Failure to replace a faulty oxygen sensor over time can also cause damage to the catalytic converter.
Damaged Catalytic Converter
The catalytic converter converts carbon monoxide into carbon dioxide. Typically, the catalytic converter will become damaged due to neglected maintenance or a problem with one of the sensors (mass airflow sensor, oxygen sensor, etc.). Your vehicle will not pass emissions testing with a faulty catalytic converter, and you can experience reduced performance in addition to poor fuel economy.
Loose or Missing Gas Cap
That’s right, one of the most common causes of the check engine light is simply a loose or missing gas cap. If the check engine light is on, make sure the gas cap is securely fastened and doesn’t appear to be cracked, chipped, or visible damaged in any way. If the gas cap looks good, bring your vehicle to an auto repair shop in Sacramento and let a mechanic perform a check engine light diagnostic to figure out exactly what’s going on with your car.