Does the Catalytic Converter Affect Fuel Economy?

Written by mike smith
  • Share
  • Tweet
  • Share
  • Pin
  • Email
Does the Catalytic Converter Affect Fuel Economy?
Empty Fuel Gauge (Jupiterimages/Stockbyte/Getty Images)

Catalytic converters are part of a car's exhaust system that reduce the amount of nitrous oxide produced by burning fuel. When working properly the converter should not affect fuel economy, but it can if it becomes clogged or damaged.

Other People Are Reading

Exhaust Backpressure

If your car's catalytic converter becomes plugged or clogged, it restricts the airflow of exhaust from the engine. This causes more and more exhaust to build up in the engine which reduces the amount of new, combustible oxygen the engine pulls in. A common cause of a clogged catalytic converter is overheating due to a misfiring spark plug.


When it is receiving less oxygen, the engine must work harder to achieve speed. This increased work lowers fuel economy, reduces power when driving at high speeds and can cause overheating and stalling. If your car runs normally for a few minutes after starting, but then begins to cough or sputter, your converter may be clogged. Especially if you have noticed other symptoms, have your mechanic check the car's exhaust backpressure.


If your catalytic converter is clogged or damaged, it will need to be replaced. Make sure to investigate the reason that the first converter was ruined so the replacement does not suffer the same fate.

Don't Miss

  • All types
  • Articles
  • Slideshows
  • Videos
  • Most relevant
  • Most popular
  • Most recent

No articles available

No slideshows available

No videos available

By using the site, you consent to the use of cookies. For more information, please see our Cookie policy.