5 MISLEADING REASONS FOR A CHECK ENGINE LIGHT -

misleading-reasons-for-check-engine-light

The check engine light serves to warn the driver that something is wrong with one or more of the car’s systems.

There are many reasons why this warning light appears. Some of them can be very misleading and easily cause unnecessary repairs at pretty high costs.

To be honest, the check engine light is infamous for this.

Well, this article will show you some of the most misleading yet simple reasons that we recommend you check first, before you go deeper into diagnosis.

Besides this website, you can also watch videos on our YouTube channel, where we have many car-related videos that may help with maintenance, driving, etc.

MISLEADING REASONS FOR A CHECK ENGINE LIGHT

1. BAD GAS CAP

The first and perhaps the most overlooked cause of a check engine light is a faulty gas tank cap.

In most cases, the rubber seal on the gas cap stiffens or cracks, and air gets in and out of the gas tank, which can eventually cause a disturbance in the air-fuel mixture.

Also, a faulty tightening mechanism on the cap can cause problems.

The solution is very easy: just buy a new gas cap.

To see some more reasons for the check engine light besides all these, click here.

2. POOR FUEL QUALITY

Speaking about gas or fuel, the quality of fuel will also cause the check engine light to appear.

Low-quality fuel causes issues with combustion, which then cause higher emissions in the exhaust fumes, and the check engine light appears.

These symptoms are very hard to notice, especially if there are no other symptoms of this problem, like misfires or rough idling.

One tell-tale sign of this symptom, although not very reliable, is that the check engine light appears intermittently or soon after you’ve poured the bad fuel.

3. AIR LEAKS

The next reason is air leaks, which are notorious for being very hard to find.

The most common reasons for air leaks are loose clamps, cracked hoses, damaged seals, and the list goes on.

The leaks are mostly present on parts of the air intake, but also in the fuel intake system, for instance.

Whatever the case, excess air causes the mentioned disturbance in the air/fuel mixture, and the check engine light appears.

4. VACUUM LEAKS

When mentioning air leaks, it’s a similar situation with vacuum leaks.

Cracked hoses and broken plastic connectors are just some of the causes of problems.

Depending on the car, one of the biggest hotspots for this problem is the vacuum hoses leading to the brake booster.

5. BAD ELECTRICAL CONTACTS

Finally, a rarer but also very often overlooked reason is bad electrical contacts.

Filth, rust, exposure to heat, and moisture are some of the reasons that can cause a bad contact over time.

How do they trigger the problem? Well, for example, you may have a bad contact on an ignition coil. The bad contact will cut off the electric supply to the coil, and it will cause a misfire and the check engine light.

A bad contact on the O2 sensor or MAP sensor, for instance, will do the same.

This is also one more reason that is very simple to fix, but in most cases, very hard to find.

CONCLUSION

In the end, we must mention that almost all of these reasons can trigger various DTC codes that, in some cases, may not have much to do with the actual cause of problems.

So, this is where the main issue is: if you’re not careful in these situations and you do not use logic and preferably some experience, besides the OBD tool, you may easily be misled.

For instance, a simple faulty gas cap or electrical contact can easily lead to losing time and replacing expensive parts.

So, please have this in mind if the check engine light appears.