Rick's Free Auto Repair Advice

How to Break-in a New Catalytic Converter So It Will Last

How to perform a catalytic converter break-in procedure

Any time you replace a converter, you must perform a catalytic converter break-in procedure before taking it out on the street. The procedure is designed to slowly expand the converter’s matting (shown below), the material used to wrap and protect the ceramic brick that’s coated with precious metals. The matting is made with  vermiculite, a fibrous mat and an organic binder materials. During the manufacturing process, the matting is compressed and wrapped around the brick. In use, the matting must expand to protect the brick. That’s where the break-in procedure comes in.

Why the break-in procedure is so important

A catalytic converter break-in procedure ensures that the mat expands in a slow and predictable way. That’s critically important because the mat loosens during the first heating cycle. Then, as it continues to heat, it expands and protects the brick. However, if you start up the engine and get it out on the street, the loose mat can allow the brick to move and break.

The instructions that come with the converter warn against street use without the break-in procedure and not doing it can void your warranty. he customer drives away and runs the car for a long distance or lets the vehicle idle for an extended period of time. Under these conditions, the matting, which is intended to secure the substrate, will not expand properly and hold it in place.

catalytic converter matting material

The matting that blankets the ceramic brick must heat up and expand in a controlled manner. That’s why following the catalytic converter break-in procedure is important

 

Here’s the catalytic converter break-in procedure

• Start the vehicle, but do not rev the engine;
• Idle the vehicle and allow it to warm up slowly;
• After 5 minutes, increase the engine speed to 2500 rpm;
• Hold at 2500 rpm for 2 minutes; and
• Allow vehicle to cool down completely.
• Road test the vehicle

©, 2014 Rick Muscoplat

Posted on by Rick Muscoplat



Custom Wordpress Website created by Wizzy Wig Web Design, Minneapolis MN