The Story
99-00 Honda Civic SI EM1 4-1 Style Header Stainless Steel
Stainless steel 4-1 header built for the EM1 platform to improve exhaust scavenging and flow. This header consolidates four runners into one outlet, reducing backpressure and freeing up power in the midrange. Constructed from mandrel-bent stainless steel for durability and corrosion resistance.
Key Features
- Mandrel-bent runners - Smooth curves maximize flow without dead zones or turbulence.
- Single outlet collector - 4-1 design consolidates exhaust gas for better spool characteristics.
- Stainless steel construction - Won't rust or corrode over time, maintains performance.
Specs
- Material: Stainless Steel
- Configuration: 4-1 collector design
- Condition: New
Whats Included
- 4-1 header assembly
Frequently Asked Questions
Will this bolt directly to my exhaust manifold gasket and studs?
Yes, this header uses factory mounting points on the cylinder head. You'll need new gaskets and studs are reusable if they're not stripped — grab fresh ones to be safe.
Do I need to prime or paint this header before installation?
Stainless steel won't rust, so paint or ceramic coating is purely cosmetic. If you want it coated for looks, do it before you bolt it on — easier to handle and cure without heat cycles.
Will I need custom exhaust piping to connect this to my downstream system?
Check your outlet diameter against your current exhaust piping. If there's a mismatch, you may need an adapter or custom section — measure before ordering any secondary work.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Details & Craftsmanship
Every detail has been carefully considered to bring you the perfect product.
Description
99-00 Honda Civic SI EM1 4-1 Style Header Stainless Steel
Stainless steel 4-1 header built for the EM1 platform to improve exhaust scavenging and flow. This header consolidates four runners into one outlet, reducing backpressure and freeing up power in the midrange. Constructed from mandrel-bent stainless steel for durability and corrosion resistance.
Key Features
- Mandrel-bent runners - Smooth curves maximize flow without dead zones or turbulence.
- Single outlet collector - 4-1 design consolidates exhaust gas for better spool characteristics.
- Stainless steel construction - Won't rust or corrode over time, maintains performance.
Specs
- Material: Stainless Steel
- Configuration: 4-1 collector design
- Condition: New
Whats Included
- 4-1 header assembly
Frequently Asked Questions
Will this bolt directly to my exhaust manifold gasket and studs?
Yes, this header uses factory mounting points on the cylinder head. You'll need new gaskets and studs are reusable if they're not stripped — grab fresh ones to be safe.
Do I need to prime or paint this header before installation?
Stainless steel won't rust, so paint or ceramic coating is purely cosmetic. If you want it coated for looks, do it before you bolt it on — easier to handle and cure without heat cycles.
Will I need custom exhaust piping to connect this to my downstream system?
Check your outlet diameter against your current exhaust piping. If there's a mismatch, you may need an adapter or custom section — measure before ordering any secondary work.
