Car Without Catalytic Converter

Car Without Catalytic Converter

A car without catalytic converter is illegal in many places.

What happens if your car has no catalytic converter? Running without a catalytic converter impact the environment badly, violate regulations in some places and also increase the pressure to the engine due to the poor air quality.

  • The catalytic converter prevents your health and the people's health from deteriorating by eliminates 98% of pollutants from reaching the air (
  • It is also violating the regulations from some states, since you will be harming human health without a simple catalytic converter, which no state wants. The United States Clean Air Act required a 75% decrease in emissions in all new model vehicles after 1975, a decrease to be carried out with the use of catalytic converters.
  • The car engine also gets excess pressure if the converter is not working or gets stuck or clogged. The engine will have a decreased lifetime due to damage to the engine.

Catalytic converter are in fact something people steal and there is now a ban of selling catalytic converter without a proof of ownership as reported in Washington Post.

McCarthy, 77, who discovered that his catalytic converter had been stolen from his 2007 Toyota Prius. “When I got in my car and started it, it sounded like a 747 aircraft without the windows. It was this loud, offensive noise, and I turned the engine off right away,” McCarthy said. “I didn’t know what to think, but something was wrong.”

Can I still drive my car without catalytic converter

Other than breaking the law, you can still drive your vehicle even if it doesn't have a catalytic converter, and it won't have any huge impact on the vehicle's overall performance. In theory, you can remove a catalytic converter and replace it with a straight pipe.

Depending on your insurance coverage, your car insurance may cover your catalytic converter replacement or problem. You can contact your insurance agent to see what your options are and whether or not you are covered.

Is it illegal to drive without a catalytic converter

It will be illegal to drive a car manufactured after 1975 to run without catalytic converter according to the US Clean Air Act.

You can simply get fined thousands of dollars for this action. Thus, as a driver, you must keep an eye and ear for any symptoms of a bad catalytic converter and replace it immediately.

What vehicles don't have catalytic converters

For vehicle before 1975, there are no requirements for catalytic converter and it will not be included, given the added cost. They are so valuable early on and still stolen till today. In fact, there are anti-theft devices in car shop with installation cost ranging from $250 to $800.

Does removing catalytic converter affect engine

A missing catalytic convert is better than a faulty catalytic converter. A bad converter might result in poorer engine performance.

Without the converter, your vehicle will no longer be filtering and reducing harmful emissions, including hydrocarbons, nitrogen oxides, and carbon monoxide. Not only is this bad for the environment, but it can also lead to harmfully poor air quality. When you park in your garage, for example, these toxic pollutants can find their way into your home.

Moreover, if we keep the side's environmental effects due to a faulty or damaged catalytic converter , the engine gets excess pressure. If the converter is not working or gets stuck or clogged, the vehicle will get stuck for sure. It will lack power, and in the worst case, you'll not be able to drive it. And this will result in engine damage and decrease lifetime.

Removing the catalytic converter decreases the pressure on the engine, and the engine can perform better. The engine would no longer have to operate twice to generate the same energy while the converter is already operating. As the engine faces less pressure, you can get a smooth ride. As a result, it contributes to lower fuel consumption and higher gas mileage.

Can a bad catalytic converter cause your car to not start

A car can start regardless of the catalytic converter since starting of the engine is based on the electrical components which exclude the catalytic converter. It is more likely due to a flat battery, when you forgot to turn off your electrical component like signal or hazard light the night before.

A catalytic converter will deteriorated due to a problem with its internal component. For instance, they might experience extreme temperatures resulting in damaging its internal seriously; thus, while you still have the parts, the vehicle will not detect it, or it will feel that you don't have a catalytic converter. 

The catalytic converter is a sensitive device with precious metals coating the inside. Without these metals, the redox reactions cannot occur. There are several substances and chemicals that inhibit the catalytic converter.

  1. Lead: Most vehicles run on unleaded gasoline, in which all the lead has been removed from the fuel. However, if lead is added to the fuel and is burned, it leaves a residue that coats the catalytic metals (Pt, Rh, Pd, and Au) and prevents contact with the exhaust fumes, which is necessary in performing the necessary redox reactions.
  2. Manganese and silicon: Manganese is primarily found in the organometallic compound MMT (methylcyclopentadienyl manganese tricarbonyl). MMT is a compound used in in the 1990's to increase fuel's octane rating (a higher octane rating indicates that the gas is less likely to combust, causing the engine to explode. This is important since higher performing engines have a high compression ratio, which would need a higher octane gas to complement the amount of compression in the engine), and has now been banned from commercial sale due to the EPA's regulations. Silicon can leak from the combustion chamber into the exhaust stream from the coolant inside the engine.


As useful as catalytic converters are, they are a target of theft or malfunction as your car aged. It is important and easy to neglect the benefit a catalytic converter has due to its cost compared to your vehicle outstanding valuation. To each of its own.

Efforts have been made to get the information as accurate and updated as possible. If you found any incorrect information with credible source, please send it via the contact us form
Author: Sky Hoon
He loved the future of self driving car and cannot wait for one. In the meantime, he loved to read up all about car and components like a computer.
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