The engine light on your Toyota Corolla is a warning sign that something could be wrong with your car. Many potential problems can cause the engine light to come on, and it’s important to know what these problems are.

Most issues that cause the check engine light to come on in the Toyota Corolla are relatively minor, but some can be more serious. Faulty sensors, a loose fuel cap, or a blocked catalytic converter can all cause the light to turn on. Knowing what could be wrong will help you determine the best solution and ensure that the problem is taken care of as soon as possible.

This article will discuss five of the most common causes of the check engine light coming on in a Toyota Corolla and explains what you can do to resolve the issue.

Toyota Corolla Engine Light – Causes

Here is a quick overview of the five most common problems associated with the Toyota Corolla engine light. 

Faulty Oxygen Sensor

Your car’s oxygen sensor carefully checks the amount of oxygen within your vehicle’s exhaust system. This information is then relayed to the engine, which adjusts fuel ratios accordingly. The engine will run inefficiently when it fails, leading to decreased performance, higher fuel consumption, and an illuminated engine light. 

The oxygen sensors on a Corolla are closer to the exhaust manifold than other cars. This makes them more prone to damage from heat and vibration.

Loose Fuel Cap

If your fuel cap isn’t properly tightened after refueling, it can cause a vacuum leak in your fuel tank. This will result in a decrease in efficiency and an illuminated engine light. This issue is easy to fix; check that the cap is tightly closed before driving away from the gas station. 

This issue is more common on a Corolla because it has an automatic seal on the gas tank lid which means you don’t need to close it tightly when you fill up with gas. This means that if you forget to close the lid after filling up, your engine light will come on because there is a leak in the system. 

Clogged Catalytic Converter

The catalytic converter is responsible for converting harmful gases into less harmful ones before they are expelled from your vehicle’s exhaust system. If it gets clogged up due to the accumulation of dirt or debris, it won’t function as efficiently. This can cause an illuminated engine light on your dashboard.

The Corolla has a particularly susceptible catalytic converter due to its positioning close to the engine. This makes it more likely for dirt and debris to get into the system, resulting in a clog and an illuminated engine light.

Low Oil Pressure

If there isn’t enough oil flowing through your Corolla’s engine, it won’t be able to lubricate its parts properly. It will also struggle to cool itself down effectively when running at higher temperatures. This can result in increased wear and tear on its components and an eventual breakdown if not addressed immediately.

An illuminated engine light can indicate low oil pressure levels. Ensure you take care of this issue quickly if you see one pop up on your dashboard display panel. 

Faulty Ignition Coils

Ignition coils provide a spark to each cylinder of an internal combustion engine, allowing them to fire up when needed during operation. Without this spark, cylinders wouldn’t be able to combust fuel properly, resulting in reduced power output and an illuminated engine light due to misfires occurring within them. 

These coils tend to degrade over time, so they may need replacing every few years, depending on how often they’re used.

Toyota Corolla Engine Light – Fixes

Fortunately, you can easily fix these problems with a few simple steps.

Replace The Oxygen Sensor

If you’re experiencing a drop in engine performance or an illuminated engine light due to a faulty oxygen sensor, you’ll need to replace it as soon as possible. This can be done either by a professional or yourself if you have the right tools and know-how. 

Check The Fuel Cap

If your fuel cap isn’t properly tightened, it can lead to a decrease in efficiency and an illuminated engine light. To prevent this issue, ensure the cap is tightened after filling up with fuel.

If the fuel cap is damaged, you’ll need to replace it to prevent any further issues from occurring.

Clean or Replace The Catalytic Converter

If your catalytic converter is clogged due to the accumulation of dirt or debris, you’ll need to either clean it or replace it. This will depend on how severe the problem is. 

You can clean the catalytic converter yourself by pouring a catalytic converter cleaner into the fuel tank. You can then run the engine for a few minutes to allow it to do its job. Alternatively, you can take it to a mechanic and have them clean or replace the part for you.

Check Oil Pressure Levels

If your engine light indicates low oil pressure, you’ll need to check the levels and top it up if necessary. You can do this yourself by checking the dipstick in the engine compartment. If the oil level is below the minimum mark, you’ll need to top it up with the right type of oil.

Replace Faulty Ignition Coils

If your engine light indicates misfires in the cylinders due to faulty ignition coils, you’ll need to replace them. Due to the high voltage in the ignition system, you may be best off taking your vehicle to a mechanic to get this done safely.

FAQ

Is It OK To Drive With The Check Engine Light On?

The best answer to this question is no. It is not OK to drive with the check engine light on in a Toyota Corolla. This warning light generally indicates a malfunction or problem with the engine, and you should inspect it before further use. Continuing to drive with this light illuminated could result in more serious problems, so you must have your Toyota Corolla serviced as soon as possible.

Why Is My Toyota Corolla Check Engine Light Flashing?

If the check engine light is flashing, this usually indicates a more severe engine issue and should be addressed immediately. Continuing to drive with a flashing check engine light could result in serious damage to the vehicle. It is usually accompanied by other symptoms, such as loss of power, so you may be unable to drive it anyway.

Can A Check Engine Light Go Off By Itself?

In some cases, the check engine light can turn off by itself. This usually happens if the issue that caused it to turn on in the first place is a temporary one and is no longer present. However, this doesn’t always happen. In most cases, the check engine light will remain on until the underlying problem is resolved.