How to Fix Reduced Engine Power | Can You Do It Without a Mechanic?



The reduced engine power light is used to alert that there is a serious problem with the transmission or one of the numerous sensors or modules of the engine system. If you’re curious to learn how to bypass reduced engine power without a mechanic, we have prepared a list of the most common potential problems that you can fix on your own.


What is and what causes reduced engine power?

Cars nowadays are more sophisticated than ever before, and while this makes them safer, easier to drive, and more reliable, it also means that once a sensor or module misbehaves, any number of error lights can appear on the dashboard.

The reduced engine power light, in particular, is the most unnerving since if it happens without triggering any other dashboard warning lights, it can be difficult to pinpoint the root of the problem. Once the reduced engine power light is activated, the car will go into a backup setting that’s also called “safe mode” or “limp mode”.

In this mode, the onboard computer will automatically decrease the power of the vehicle in an attempt to try and prevent damage to the engine. The way in which the reduced engine power limits the performance of your vehicle depends on the make and model of your car.



Sometimes the reduced engine power can just shut down accessory components and limit your speed, but with some vehicles, it can also immobilize the car completely. However, in most cases, the car will give you enough power to get back home or to a repair shop.

While there are situations where only a mechanic can fix reduced engine power, the good news is that if the error happens without triggering any other warning lights, this might be a clue that the issue might be something that you can fix on your own. Below you can find all of the four most common possible issues, so make sure to continue reading.


Dirty air filter

The air filter in your car helps clean up the air that’s entering your engine so that dirt and other contaminants can’t get to the main engine. It helps keep the engine clean and running smoothly and efficiently.

With time, the filter can experience a buildup of contaminants, and if too much debris gets stuck in the filters, the airflow that can reach your engine will be restricted. Air is an essential part of the combustion process since, without it, your engine cannot run efficiently.

Since there is no way to monitor the accumulation of dirt and debris on the air filter, you won’t get a warning light to notify you that something is wrong with it. Instead, you will notice the reduced engine power light.

First, you will need to inspect the air filter to see if it is clogged. Start by identifying the location of the component. On most cars, the filter is found in a rectangular plastic box that’s located on one side of the engine block, right next to the inside of the fender.

Older car models will use a large round container that is fitted atop the engine block. If you have difficulty finding it, you can refer to the vehicle manual by looking for the “Cold Air Collector Box”.



To check the status of the filter, you will need to open the container and remove the filter inside. Take the filter out and position it up to a light source. If little or no light comes through the filter, then this is a sign that it is clogged.

If the filter is clogged, the best approach is to replace it with a new one, but if that’s not possible at the moment, you can tap it gently against a hard surface until all the dirt and grime have dislodged. If the filter is still clogged, then it means that there is no way to fix the filter on your own, and you’ll need to buy a replacement.

As a general rule, you can avoid problems with the air filter by replacing it every 12 months. You can also consult your car’s repair manual or owner’s manual to see what your car manufacturer recommends.


Dirty air sensor

Your car has anywhere between 60 to 100 sensors, and this component is one of them. The air sensor is the gadget that’s responsible for monitoring the quality of the air that is drawn into the engine. As you probably already know, without air, the combustion process cannot happen. This is why monitoring the air intake is very important.

The way that this sensor works is very simple. It lets air pass over a heated wire, and the temperature of the wire decreases or increases depending on how strong or weak the airflow is. With the data from the sensor, the engine knows if it needs to decrease or increase the amount of fuel that it uses.

However, if the heated wire inside the air sensor gets dirty, the data the sensor gives will no longer be reliable. This can cause the engine to inject less gasoline than it needs, which in turn will lead to a reduction in engine power.

There are two ways to tell if the reduced engine power is due to a dirty air sensor. The first method is to locate the sensor, start the engine, and give the sensor a few sharp taps. If, after tapping the sensor, the engine falters a little, it means you have a dirty sensor.

The second method is to disconnect the sensor and start the engine. With the sensor disconnected, the engine will go into the back-up running mode. If in this mode, you notice that the engine runs better, this means that the sensor is either dirty or damaged.

To clean the sensor, you can purchase an air sensor cleaner at your local auto shop or online. Remove the sensor and follow the instructions on the cleaner can. If the sensor is damaged, you will need to replace it with a new one.



Weak fuel pump

The car engine works by burning a mixture of air and gasoline. Gasoline is pumped along a pipe from the fuel tank and mixed with air in the carburetor. It is from the carburetor that the engine sucks the mixture of air and gasoline. The fuel pump is the component of the car that draws the gasoline out of the tank and through a pipe to the carburetor.

The pump can be worked mechanically by the engine or can be electric. If the fuel pump is electric, then it can be positioned next to or even inside the fuel tank. With time, the pump can start to age, and it will lose its effectiveness.

To prevent damage to the fuel pump, you should try to top up your tank frequently since the fuel inside the tank is also used as a coolant to keep the fuel pump from overheating. Driving your car with a low tank frequently can shorten the lifespan of the fuel pump.

If you suspect the fuel pump to be the cause of the reduced engine power, you will need to check the pressure using a fuel pressure gauge. If the readings show that there is a problem, you will need to replace the fuel pump.

While changing the fuel pump is something that a good home mechanic can achieve, it is more involved than some of the previous jobs. As such, it might be better to get a mechanic or a skilled friend to help you with this part.


Old catalytic converter

The catalytic converter is a device that is used to convert hydrocarbons, nitrogen oxides, and carbon monoxide into harmless compounds. It is a component that is fitted into all cars that are built after 1975.

It is illegal to drive a car without having a catalytic converter installed since, without it, the exhaust gases produced by the engine would remain highly poisonous. When the converter works properly, it won’t cause any major loss in performance as it will only produce a reduction in power of 1% to 3%.

However, if the catalytic converter malfunctions, it can restrict the flow of exhaust gases. The converter is attached to the exhaust system under the car, and it can be easily recognized thanks to its long and rectangular box shape.

The interior of the converter is filled with a metal honeycomb structure, and older models may have ceramic beads instead. With time, the beads or the honeycomb can clog with contaminants. In this situation, the exhaust gases can’t exit the converter properly, which will have an impact on your engine’s performance.

Unfortunately, there is no way to fix the catalytic converter once it has started to wear down, and the only solution is to buy a new one and replace it. Catalytic converters are expensive, but you can keep costs down by installing the new one yourself.