Can a Hole in Your Muffler Cause Check Engine Light?

Can a Hole in Your Muffler Cause Check Engine Light

A muffler is an important part of the exhaust system without which there will be a lot of noise coming from the exhaust.

The muffler is made of metal therefore it is susceptible to rust, this rust in turn leads to holes in the muffler. When this happens, there will always be a telling sign but can a hole in your muffler cause check engine light?

A hole in the muffler can cause the check engine light to come on. This is because the fresh air coming from the hole will cause the o2 sensor to give a false reading which will trigger the check engine light to come on.

What is a Muffler?

A muffler also known as a ‘Vehicle Silencer’ is part of a vehicle’s exhaust system made of metal and helps in the reduction of noises coming from the exhaust and engine.

A large number of burnt gases used when internal combustion takes place in an engine are released into the exhaust system and then let out through the exhaust valve when it opens.

The muffler is designed in a way that allows sound waves (burnt gases) to bounce off its wall.

Mufflers have tubes and perforations that help to direct sound waves inside, through, and out of them. The presence of mufflers in a car makes it possible for the car to be calm despite the explosions going on in the engine.

What Causes Hole in Muffler?

Since a muffler is part of a vehicle’s exhaust system, over time you may begin to see signs that there are holes in it.

Holes in the muffler may leave one wondering as to how they got there or the causes. The most notable cause of holes in mufflers is Rust and rust can be a result of various things.

1. Corrossion

The first cause may be as a result of Corrosion. If holes in the muffler are caused because of corrosion, it means the metal has deteriorated due to oxidation.

This tends to happen when the muffler interacts with air and water over time which leads to its rusting. Rusted metal will eventually have holes in them.

2. Road Salt

The holes in mufflers could also be a result of Road Salt. Road salt is the mineral form of Sodium Chloride and is a common component used in deicing highways.

One of the disadvantages of road salt is that it causes car parts to rust, the vehicle muffler inclusive. Because vehicles are driven on roads and highways all the time, they come in contact with this salt that over time causes the muffler to rust and have holes in them.

3. Impact

Another cause of holes in a vehicle’s muffler is Impact. The impact driving will have on a vehicle and the muffler will depend on the driver’s driving habit.

For a person that drives roughly, the impact on the vehicle will be great compared to someone that drives at normal speed.

Also, the impact of driving over potholes, bumps, and other hazards very fast will damage and cause holes in the muffler.

4. Condensation

This is created in the exhaust when the car is started, if the muffler is not allowed to heat up and let out the water, holes will develop at the water spot in the muffler.

Can a Hole in Your Muffler Cause Check Engine Light to Come On?

Yes, a hole in the muffler can cause the check engine light to come on. When the check engine light is on, it is usually as a result of a trigger, in this case, the O2 sensor.

What to Do If There is a Hole in Your Muffler?

One major determinant as to what should be done to holes in a muffler is the size of the whole. The sizes of holes in a muffler vary and may depend on the cause.

If the hole is small all that needs to be done is have it repaired by covering but if it is much bigger then you will need to replace it.

Repairing and covering muffler holes can be as easy as using a JB Weld. JB Weld is in small packages and is highly durable.

All you have to do is get a knife, preferably a plastic knife, scoop some of the substance, and apply it to the holes. Leave for some minutes to allow the JB weld to get dry on the surface, the aftermath will be a solid rock surface. This will do the trick of covering up the holes.

The other option to cover the hole is employing the service of a professional welder. Since mufflers are made of metal, a welder can also do a good job of patching the holes. The welder gets a sizable metal sheet and welds it on the hole.

In covering up the holes, you should know that this is only a temporary solution. More holes will appear beside the one covered soon enough because the muffler metal is already thin due to rust.

A lasting solution will be to completely replace the muffler if you can afford it.

Other Things That Can Cause Check Engine Light

The check engine light coming on in a car could mean so many things, other than holes in the muffler there are other things that could cause this to happen. Here are some of the other things that could cause the check engine light to come on.

Bad Catalytic Converter

The catalytic converter is responsible for converting harmful carbon monoxide to environmentally friendly carbon dioxide.

If this gets faulty, a couple of things will happen such as; a reduction in the fuel economy, increased emission, and of course, the check engine light will come on.

Bad or Loose Gas Cap

The gas cap ensures vapor doesn’t get inside the gas tank but over time it can go bad or become loose. A loose or bad gas cap will also cause the check engine light to come on.

Faulty Mass Air Flow Sensor (MAF)

The mass air flow sensor helps to determine the amount of air that enters the engine in order to accurately get the air-fuel ratio.

If the MAF sensor gets dirty or faulty, the check engine light will be triggered on the dashboard. Failure of the MAF will also cause reduced performance and fuel economy.

Bad Spark Plug or Spark Plug Wires

A bad or worn spark plug can cause a couple of things to happen in the engine such as misfiring, check engine light coming on, hesitation, etc. If this is not fixed quickly, it could result in the car shutting off.

The spark wire plug is responsible for the transfer of electricity from the coil to the spark plug, If it is bad, the cylinder won’t ignite and the check engine light will also be on.


The check engine light can be on for lots of reason that has nothing to do with holes in the muffler, therefore, you should troubleshoot properly to determine the real cause.