Exhaust› Headers, Manifolds and Components

1320 Performance

4-2-1 Header with Catalytic Converter

$395.00

SKU: 1320-bb6-HD-2.5-base

Special Order
Special Order
Ships in 4–6 weeks
Free Shipping over $200
$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The 1320 Performance header is a T-304 stainless steel exhaust manifold designed for performance.

It features a 4-2-1, 2-piece design with mandrel-bent tubing and Tig welds for durability. The header includes a high-flow 2.5-inch collector and an EPA-approved 2.5-inch catalytic converter.
Show original supplier description
The 1320 Performance Stainless Steel Header is crafted from robust T-304 stainless steel with a brushed finish, ensuring durability and resistance to cracking. Its mandrel-bent construction and TIG welded seams contribute to longevity. The header features a 4-2-1, two-piece design and a high-flow 2.5-inch collector, which is larger than the OEM 2-inch collector, to improve exhaust gas flow. It includes an EPA-approved 2.5-inch catalytic converter with flanges for both the header and exhaust. Note that the catalytic converter will require welding by a muffler shop to integrate with your specific exhaust setup. This header is designed exclusively for the 1997-2001 Honda Prelude Base model (Non-SH). It is also compatible with pre-1965 classic vehicles that have had an H22A4 engine swapped in. A crucial installation note: If your vehicle does not have aftermarket solid motor mounts, do not connect the 2-bolt bracket on the down-pipe to the engine block. Using this bracket with OEM motor mounts can lead to bracket weld breakage due to excessive engine movement.
Vehicle Symptoms
  • Check engine light illuminated (P0420)
  • Rattling noise from exhaust under acceleration
  • Reduced fuel economy and engine performance
  • Sulfurous smell from exhaust
  • Failed emissions test due to catalytic converter
Diagnostic Codes
  • P0420 – Cat Sys Efficiency Below Threshold (B1)
Relevant Conversations
  • P0420 code on 1998 Honda Civic
  • 4-2-1 header vs 4-1 header dyno
  • Will a header fix my P0420?
  • Best exhaust header for 1999 Honda Accord
  • Check engine light after cat replacement
  • T-304 vs 409 stainless header
  • Honda D16Y8 header with catalytic converter
  • Exhaust upgrade for 2000 Honda Civic LX
  • Replacing O2 sensor and header together
  • Emissions test fail – catalytic converter replacement

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

Brand1320 Performance
Part Number1320-bb6-HD-2.5-base
CategoryExhaust
5,000+ Trusted brands
1M+ Enthusiasts
5M+ Parts sold
(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

View Full Return Policy

Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy