Which header is typically shorter length, dimpled, and connects to emission control devices?

• A. Stepped Header
• B. Zoomie Header
• C. Dyno Header
• D. Stock Header

Answer: (D)

In exhaust systems, the design of the header shows a balance between fitting under the hood, matching the rest of the exhaust, and working with the vehicle’s emission-control devices. A stock header is the OEM part made to work with catalytic converters, oxygen sensors, and other emission controls, so it’s typically designed to be shorter and to fit cleanly with the rest of the system. The dimples you sometimes see on stock manifolds are a simple, cost-effective way to manage heat and flow in mass production, while still keeping the system compliant with emissions regulations.

Other headers—stepped, Zoomie, or Dyno—are geared more toward maximizing performance. They usually use longer or differently tuned runners and designs that may not integrate with emission controls as neatly, and they’re not typically built with the same emphasis on fitting around sensors and converters.