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Do Diesel Engines Have Catalytic Converters?

September 21, 2022

Catalytic converters are something regularly spoken about in several circles; this is because catalytic converter theft is on the rise in Canada. If you’re wondering if your diesel engine has a catalytic converter, the short answer is, many do. Read our blog to learn more about your diesel’s catalytic converter!

What is a Catalytic Converter?

A catalytic converter is part of your vehicle’s exhaust system. They are designed to reduce airborne pollutants due to a call to reduce dangerous emissions from vehicles. Catalytic converters were originally designed in the 1970s for gasoline engines, but catalytic converters started being installed in diesel engines in the 1990s. 

Catalytic converters reduce the impact of over 90% of harmful emissions and toxins by converting them to carbon dioxide and water – including carbon monoxide, nitrogen oxides, and hydrocarbons. In short, catalytic converters ensure that vehicle engines are healthier for the environment and for humans. 

Do All Diesel Engines Have Catalytic Converters?

Whether or not your diesel engine has a catalytic converter depends predominantly on what year your model is. Because diesel engines are requested to meet non-toxic emissions standards, almost all diesel engines made after the year 2000 will have a catalytic converter to reduce the vehicle’s toxic emissions. If your diesel vehicle was made before the 1990s, however, you will not have a catalytic converter.

How Do Diesel Catalytic Converters Work?

Diesel engine catalytic converters are different from gas engine vehicles, but the concept in that they introduce oxygen to neutralize harmful gases remains the same. In a diesel catalytic converter, the interior of the metal casing has two ceramic blocks with thousands of micro-cellular units. These ceramic blocks are coated with precious metals, usually palladium and platinum, that heat the blocks up and catalyze the chemicals – turning them into harmless gasses. One primary difference between diesel and gasoline catalytic converters is that diesel catalysts do not use rhodium, also diesel catalytic converters have an attached diesel particulate filter to eliminate any of the particular matter that comes from diesel engines. 


How long do diesel catalytic converters last?

Diesel catalytic converters typically last around ten years or over 160,000 kms in driving. 

Why are diesel catalytic converters different from gas catalytic converters?

Diesel engines typically run much cooler than gas engines, so they need a different process to ensure that the toxic substances are successfully neutralized.

What are signs your catalytic converter is failing?

There are a few reasons a catalytic converter would begin to fail such as carbon build up, overheating, physical damage, and contamination. Signs your catalytic converter is defective include:

  • Dark smoke from exhaust
  • The smell of sulfur
  • Decreased acceleration power
  • Slow engine performance
  • Your engine is overheating

Why are catalytic converters stolen?

Catalytic converter theft is on the rise because of the precious metals within them. The converters are broken down for the price of their scrap metal. 

Signs your catalytic converter was stolen:

  • Your check engine light is on
  • Your engine is making a very loud noise
  • You get a headache when your windows are down
  • Reduced low-end torque
  • You’re missing components from under your vehicle

DFC Diesel remanufactured engines the highest quality engines available. Check out our Duramax, Cummins, and Powerstroke reman engines. If you have a question about your diesel engine, please contact us!