Top 10 Reason why Your check engine light is on.

hello, I am doctor cool auto fix.

in today video, i will be teaching your top 10 reasons why your check engine light is on.

if you are coming to my channel for the first time, subscribe to my channel now, click on the bell icon and seat back and watch.

check engine light is a way wich the engine electronics control module communicate with the driver about engine critical component that is on the fright, sometimes it could be as simple as a loosed gas cap that is not tightened well enough, as this loosed gas cap allows fuel fumes to escape into the atmosphere, it is unsafe for the enviroment, due to this fact that fuel fumes are product of hydrocaborns that isn't friendly with the enviroment, thats why your car manufacturer coded your ecm to throw check engine light at the event of a loosed gas cap, a simple tightning of this loose gas cap to specs might solve the check engine light issue.

in other words, there other common engine commponent that are engineered to ensure the smooth operation of your car engine. in this content, I will be brief with teaching you this simple engine electronics, dont be alarmed, most of them are easy find and easy replacement when they get bad.

1. A bad ignition coil p0350 to p0353.

igntion coil is among the top engine electronics component engineeered to turn your 12 volts battery into 20 thousand volts, this will be the visible blue sparks that your spark plugs uses to ignite the air fuel mixture in your engine cumbustion chamber,
take the ignition coil like a transformer that you will find across the street of your residence,
when the ignition coil fails, you will have poor engine performance, when that occurs, the ecu will throw a check engine light, most igntion coils last up to 100 thousand miles before failing.

2. bad mass air flow sensor p0100-p0104 or map sensor p0105-p0109

mass air flow sensor aslo known as maf sensor and map are tasked to do the same job in different engine configuration, to report accurate data about the mass of air flowing into your engine to mix with fuel, the right quantity of 14.7 part of air has to mix with one part of fuel to cumburst correctly,
when these maf sensor gets dirty or failed, it will feed the ecu with false data about the mass of air going into your engine, most times over a long usage of your car, this maf sensor get clogged with dirts and debris out of a bad fuel filter, this is mostly common problems with cars driven in a dusty enviroment. this dirts coat the sensing area of your maf sensor, which in turns shield it from taking the data correctly, and result into false report, before replacing your maf sensor, try using a mass sensor cleaner to clean this sensor first and double check, clear the error code, if it persist then replace it cos when it fails. it disrupt the smooth oparation of your engine, which will make the ecm to throw a check engine light

3. bad o2 sensor or oxegen sensor, p0130 - p0167

o2 sensor is a an engine electronics component engineered snd tasked to measure the amount of unbunt oxegen in your exhaust after comburstion, then report this information to the engine electronics management ecm, the ecm uses these data to adjust the air fuel ratio of your car according to the data it recieved from the oxegen sensor, two bank engine configuration will mostly have 4 o2 sensors, two upstrean And two down stream o2 sensor, most o2 sensor last between 50 to 60 thousand miles, when o2 sensor failed, your car will have poor gas millage or run lean, meaning, it runs more on air than fuel witch in either case is not suitable for the welbeing of your engine. at this jucture, the ecm will throw a check engine light as if unattended to, can compromise the lifespan of your engine.

4. bad spark plugs.

if you are a car owners who is extramely busy, you will likely not know what, where and when about this component called spark plug, spark plugs as the name imply is an engine component that create spark that igninite the air fuel mixture present inside your comurtion chsmber, pricisely on the 3rd stroke of your comburstion circle, if the spark plug failed to ignited the air fuel mixture due to carbon deposite or fauling, this will result into engine misfire, reduced engine power, and ecm throwing a check engine light.

5. bad coolant temperature sensor. error code p1116

engine coolant temperature sensor is a component, a themistor engineered to give accurate report to your ecm as a much as you the driver, this information is used by the ecm to determine how cold or hot the engine is. some car make are often equiped with two, one for engine temperature to alert the driver of the engine temperature, A fail safe component against engine overheating, the second temperature sensor is a coolant temperature sensor, this sensor reports to the ecm of your car about the coolant temperature and engine temperature, this information is vital for engine cold start up procedure as much as fuel efficiency of your car. when this coolant temperature goes bad. your ecm will have trouble manegine your air fuel mixtures, this will lead to poor gas milage, crank no start and poor engine performance, that is the core reason why the ecm often throw a check engine light when this sensor failed.

6. bad intake air temperature sensor, p0110 to p0115.

intake air temperature sensor, is a an engine component engineered to feed the ecm the temparture of air going into your engine, the ecm uses this IAT sensor to enhance the fuel efficiency of your car and ensure smooth opartion of your engine, when this sensor failed, your car will expirience an idle surge, smell of raw gasoline and poor gas milage as much as engine underpeformance, at the cause of failure, the ecm will throw a check engine light to draw your attention.

7. bad throtle position sensor.
throtle position sensor is a sensor within the engine compartment, the throtle position is a potentiometer or variable resistor that is tasked with sensing the position of the butterlfy valve present inside your throtle body, then relay this information to your ecm, the ecm uses this sensor to calibrate the proper air fuel mixture going into your engine to be ignited, when it goes bad, your ecm will throw a check engine light as it can create stalling, hard start and poor gas milage.

8. bad egr valve, p0400-p0408 error code.
egr valve stands for exhuast gad recirculation, this valve recirculate the hot exhaust back in colder form to reduce hamful gases created when air and fuel is ignited in your engine, when egr valve failed, it can get stuck open or close, which either way wont carry out duty it was primarily engirneered for, at the event of failure mostlye due to caborn deposite, will prompt the ecm to throw a check engine light.

9. bad crankshaft or camshaft position sensor, p0335 - p0339 or p0340 - p0344

gone are those days when car engine are equiped with carburator, this days, the hall sensor that is present in the distributor is now relocated to camshaft position of your engine, this now nown as camshaft position sensor, this current engine are equiped wih crankshaft position sensor is engineered to inform the ecm on which cylinder to ignite, when these sensor failled, the ecm will throw a check engine light, at this juncture, the ecm will be clueless as which cylinder to fire, this will result into car crank but will not start up.

10. bad catalytic converter, p0420-p0434. catalytic converter is engine component, engineered to convert haful substances such as sulfur and co2 created after comburtsion into harmless gasses, before getting out of your exhsust system, when the catalyctic converter failed, co2 gets detected by the downstream o2 sensor, the downstream o2 sensor will feed this information to the ecm to throw a check engine light, with error code p0420, which will be interpreted as catalyst perfprmance below threshood, most catalytic convert last between 100 to 150000 miles, this component is very expensive to replace both in part and labour, error code is p0420

although there are other causes of check engine light but these are the top 10 cause of check engine light. reason being that other engine component xan last the lifetime of car.

I remain doctor cool auto fix, subscribe to my channel, turn on your notication, give this video a thumbs up, share these content with others.

see you later in my next video.



Top 14 symptoms of bad fuel injector.

Modern cars are built with fuel injection engines in replacement to the use of Carretta.

These engines use fuel injectors to inject Sprinkle gasoline fuel into the engine cylinders for combustion to occur.

However, for pretty different reasons, fuel injectors can get clogged, damaged or failed completely.

A bad fuel injector is a serious issue to get really worried about because it puts the engine at great risk.

But how do you know that your car's fuel injectors are bad?

Now, let's quickly learn more about these bad fuel injector signs. What is a fuel injector?

If this is the first time you're hearing about fuel injectors, it's nothing to worry about actually.

The fuel injector is part electrical component of the engine, and it plays an important role of injecting fuel into your engine.

the fuel injector system receive command from the engine electronics management in a pulse modulation signal.

this component and fuel pump all combine to make up the fuel delivery system. The fuel delivery system works in a simple way.

The fuel pump takes fuel from the tank, pressurizes the fuel to pass through the filter and delivery lines into the injector.

The injector then calculatingly sprays the fuel into the cylinders for combustion to occur to keep the engine running.
when the fuel injector is bad, clogged or damaged it, it sprays too much fuel or too little fuel which would affect combustion.

And in turn affect the engine's overall performance. Fuel injectors are controlled by the ECM.

It is the ECM that tells the injector how much fuel to spray, Sprinkle into the cylinders.

What causes fuel injectors to go bad? The common problem with fuel injectors is clogging or leaking.

When the fuel injectors are clogged, they'd either not spray fuel at all into the engine or mess up the spray intervals which would be detrimental to the wellbeing of the engine and its other components.

You may want to ask what clogged the fuel injectors. It's simple dirt.

Fuel injectors get clogged from hydrocarbons, sediment and other contaminants in the gasoline fuel that passes through them.

Some fuels and gas to contain fine impurities which over time can clog the injectors.

Also, the injectors can get clogged by fumes and debris.

Once the injectors are unable to spray sufficient fuels at accurate intervals, the engine would suffer the consequence and that's when you start experiencing any of the symptoms below.
symptoms of a bad fuel injector.

1. misfiring cylinder engine. This is practically the most common symptom of a bad fuel injector,
when one or more fuel injectors go bad.

The engine cylinders connected to the bad fuel injectors would constantly misfire due to a lack of sufficient fuel supply from the injectors, engine misfires affect acceleration and fuel efficiency as well as cause little vibrations while driving.

If you notice that your car is misfiring.

One of the things to check and troubleshoot is the fuel injectors.

2. mediums or serious engine vibrations. you've experienced serious vibrations when your car is idling.

The vibration happens when the fuel in the cylinders has been utilized and the bad injectors hasn't sprayed more fuel yet.

The vibrations occurring due to clogged injectors, starving the engine the right fuel quantity it needs to function correctly.

3. check engine light is illuminated.

Yeah, there are many things that trigger the check engine light to come on.

A bad injector is part of those things.

When the check engine light comes on, it is important to use an OBD2 scanner to troubleshoot the actual faulty component that triggered the light to come on.

4. rough idling, rough idle is a way which the ECM uses to notify the driver of a problem with engine electronics critical component ECM
it is not normal for a car to shake while idling.

If this happens, it is due to a faulty engine component and it could be the fuel injectors.
once the combustion process is tampered due to insufficiency fuel as a result of a bad fuel injector.
it throws a lot of things out of proportion and can cause the car to shake by rough idling, meanings that your car shakes or sputters while waiting in traffic or when you stop to buy a thing from a roadside shop.

If this is allowed to linger, it can lead to more expensive damages in no distant time.

5. engine stalling, engine stalling refers to the unexpected sensation of the engine about to shut off. you may experience this while driving, stalling is caused by a wide range of faults in the engine bay that is majorly caused due to lack of sufficient fuel supplied to the engine.
that said, a bad fuel injector can cause the engine to stall.
while engine stalling is not a major issue to be concerned about it Calls for concern if it happens pretty often inconsistently, six increased fuel usage.

6. increased fuel consumption. If the fuel injector is not clogged but faulty, there are chances that the faulty bad injector would spray more fuel than it supposed into the engine. due to broken rubber seal present inside the injector. and this would lead to an increase in fuel consumption when you notice that your car is consuming more fuel than it used to.

That's a sign that you should check the fuel injectors.

Also, it is important to note that when more fuel is sprayed into the combustion chamber, most of the fuel would be wasted after the required amount has been used for combustion.
7. inconsistent RPM. this is often caused by bad fuel injector spraying too much fuel into the engine cylinder would trigger a surge in the engine which would result in slower acceleration and fluctuating R PM.

You'd notice that the RPM gauge is never stable when the car is running with a constant load, fuel leaks.

If the bad fuel injector is spraying too much fuel, the excesses would get into different parts of the engine and leak out from any possible spot.

Also, the fuel injectors can crack due to several reasons and thus fuel can leak out from the cracked spots.

you'd notice this by seeing fuel leaks dropping from the engine bay.

Of course, this is dangerous and can cause an explosion.

If a fire is brought close to the place where the leaked fuel touched the ground floor, ▪ the fuel injector seal deteriorates over time and it is the major cause of fuel leaks when it relates to a bad injector,
9. fuel smell odor.

As you may guess this goes along with the leak.

If fuel is leaking out, you'd perceive the odor while driving, this is a safety hazard and if you drive a passenger car, your passengers won't be comfortable sitting inside a car with such a bad smell.

10 engines won't start at all. Yeah, a bad injector can make a car undrivable. How's that possible?

When the engine is not getting the appropriate amount of fuel it needs to function over time.

The engine components would start to fail and that can cause the ECM to stop the engine from starting up.

11. dirty exhaust emission. It is possible for dirty exhaust emissions to result from a faulty fuel injector.

An engine cycle ends at the exhaust stroke where dirty gasses are expelled into the atmosphere.

An insufficient or abundant fuel supply can be caused by a malfunctioning fuel injector in either case, combustion enhances the production of unwanted gasses.

The dirtier gasses produced; the more pollution produced
12. unstable engine.

The symptoms of a bad fuel injector may appear as unstable engine R PM.

You will know faulty combustion is the cause of any symptom if you dig deep enough.

Since each rotation of the drive shaft is powered by the engine cycle, the power of the output shaft fluctuates due to incomplete combustion.

13 Engine Backfire engine backfire are symptoms commonly associated with system fuel starvation or unburned fuel dump into the exhaust manifold system.

This can result into backfire, also known as pop sound, when the engine is starved of the right fuel quantity that it needs to keep the engine running smooth.

It creates hiccup or pop sound while attempting to function correctly.

14. engine runs lean, most often times when a check engine light popped up and you plugged your scanner to it, but you are getting a lean error code which can be reporting air fuel mixture ratio components such as oxygen sensor doesn't necessarily mean that the oxygen sensor is bad but problems like fogged injectors can create a high fuel restriction which will result into the engine running very much disproportionate on air than fuel.

How to fix a bad fuel injector. If the injector is broken or cracked, sadly, you can't fix it.

You'd have to replace it with a new one. Fuel injectors are not too costly to replace.

However, the replacement should be done by a professional or experienced auto technician to avoid tampering with other critical electrical components that make the engine work.

On. The other hand, if the injector is clogged or dirty, you can clean it out yourself following diy procedures.

Fuel injector replacement costs, you can buy a fuel injector cleaner package.

You typically find them for $10 minus $20 in most auto shops online and offline.

However, if you'd have a professional, do the cleaning expect to pay around $50.

When you confirm the fault is from a bad injector, you can either clean out the injector or replace it.

The average cost of replacing fuel injectors is between $300 and $500 depending on the car model and design labor costs can go up to $200 in some mechanic shops.