What Does a Catalytic Converter Look Like On a Car?

Reviewed by

Richard McCuistian, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on September 12th, 2025

Reading Time: 2 minutes

Summary

  • A catalytic converter looks like a cylindrical metal container with a pipe on each end, similar to a muffler, and often has a heat shield.

  • Inside, it has a honeycomb structure coated with palladium, rhodium, and platinum that react with exhaust gases.

  • It sits between the engine and muffler, with one or more units placed along the exhaust system before the muffler.

A catalytic converter often looks like a cylindrical metal container with a metal pipe sticking out of each end and will usually include a heat shield. It looks like a muffler with a pipe on both ends. 

From the inside, the catalytic converter has a honeycomb-like structure that’s coated with precious metals like palladium, rhodium, and platinum, which help convert exhaust emissions into less harmful substances. 

Typically, there will be a light-off catalyst for each bank of cylinders very near the engine and one or two secondary oxidation catalysts farther back on the exhaust system. The muffler will be after the catalyst as you follow the exhaust system toward the rear of the vehicle. These photos show both catalysts on the same four-cylinder vehicle. | Image Source: Richard McCuistian

Tips On How to Access the Catalytic Converter

The catalytic converter sits between the engine and muffler, so you’ll need to raise your vehicle to get a better view.

If you’re planning to remove your old catalytic converter, make sure that the engine has cooled down completely. Note that, in many cases, the catalytic converter is part of the exhaust system and it may be difficult to remove, so don’t get in over your head if you haven’t done a lot of wrench work.

Catalytic converters are often attached to the vehicle using bolts, which you can loosen with the help of penetrating oil and a trusty wrench. 

Also, make sure to remove the rear bolts first before the ones in front.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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Published by
CarParts.com Research Team and Richard McCuistian, ASE Certified Master Automobile Technician