Check engine lights (CELs) draw various reactions from car users, from immediate panic to utter ignorance. But if you have a check engine light on, there are two possibilities that you need to consider: whether your check engine light is flashing or stable. The former would almost always happen when you are driving the car and represents a computer system emergency. This means that if such a thing happens to you, pull over at the nearest safe location and call roadside assistance. If you get a stable check engine light while you are driving, pull over at the next exit and examine your engine bay.
Make sure your petrol tank filler cap is on tightly.
Your car’s mass airflow sensor is located upstream from the throttle body, and has a wire attached with a coupler. A clogged MAF sensor can be easily cleaned with a Mass Airflow Cleaner spray.
Check your air filter to make sure it isn’t clogged.
Refer to the level markings on your coolant reservoir too make sure it is full. Then, turn on your engine and wait for the thermostat switch to open the valve. Your cooling fan will come on immediately when the valve opens. Coolant level should not fall below the minimum mark on the reservoir. If it does, add the appropriate water-coolant mixture to the radiator.
Inspect your cooling fan to ensure that it intermittently turns on and off. Whether your car is equipped with one or two fans, both must come on when you turn on the air conditioner.
If both fans are continuously on with the air conditioner turned off, this is indicative of a bad coolant temperature sensor.
The check engine light is your car's computer trying to communicate with you about an error or malfunction that has been encountered. The appropriate and requisite response to a check engine light is a comprehensive scan through the On-Board Diagnostic port. OBD-I error codes are displayed when you turn on the ignition, as a flashing light. Count the number of times that the light flashes, and that’s your error code number. OBD-II module is both a memory and control unit for your car's computer, and requires a scan tool for diagnosis. You can always do the scan yourself with the right scan tool and your vehicle's service manual. But an experienced technician will have complex diagnostic equipment and a better chance of solving the issue with the minimum amount of effort and money. Some codes like for airbags and emissions control systems can only be removed with advanced (and expensive) tools by a technician or at the dealership.
Preventive measures to prevent engine malfunction
Change your engine oil at the appropriate interval. If you don’t know what that is, and if you have an older car, check with car owners manual.
Flush the cooling system once every 5 years and fill up with new coolant.
Check your engine often. tug gently on all couplers to see if they are on tightly.
Ensure that your battery terminals are clean.
Inspect oil and coolant regularly, check for discoloration and change in consistency.
Ignoring a check engine light is like knowing you have high blood pressure and refusing blood tests or medication. Small issues can spiral into catastrophes that may render your vehicle useless or too expensive to repair. In any case, having a check engine light on means that your car is not in its best shape, which means that it will not give you the performance and efficiency that it was designed for. Most people will avoid getting their car scanned because the scan itself costs money and their car runs fine. But in such cases, it is either a problem that is a disaster waiting to happen, or it is just a sensor failure. While the former may set you back by a few hundred to thousands of dirhams, the latter will cause your car to run in a worst-case scenario sort of way. For example, if your check engine light is due to a bad O2 sensor, the computer will lean the air-fuel mixture going into the engine. This will cause you to have a lot less power, jerky throttle even with a steady foot, and cause your catalytic converter to heat up since lean mixtures have higher exhaust temperatures. Eventually, this will ruin your catalytic converter and cause your vehicle to fail RTA tests even.
A hot catalytic converter is the leading cause of vehicular fires in the 20th century. With modern cars becoming more electronically complex, the effect of the check engine light is not limited to just the engine. The on-board diagnostics interact with all electronic control modules and sensors on our vehicles to ensure their functioning and your safety. Take care of your car so it can take care of you.
P.S. I have been writing this since few days for an "exceptional post", hope reply also qualifies as admin didn't responded to the guideline of exceptional post request.