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Home > Catless Downpipe Exhaust for 1997-2005 K04/RS6 Fits Audi S4 B5 A6/Allroad C5 2.7L BiTurbo 3"-2.5"
SPELAB catless K04 downpipe pair kit for 1997-2005 Audi S4 B5, A6 and Allroad 2.7L BiTurbo, shown with two 3-inch to 2.5-inch stainless pipes, connector tubes, V-band clamps and gaskets beside the branded box.
Pair of catless K04 downpipes for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, mandrel-bent T-304 stainless with flex sections, laid out with two perforated gaskets and V-band clamps.
Complete catless K04 downpipe set for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, two mirror-polished 3-inch tapering to 2.5-inch pipes with connector tubes, V-band clamps and gaskets.
Single catless K04 downpipe for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, mirror-polished T-304 stainless with braided flex joint, CNC flange and mounting bracket tab.
Close view of a catless K04 downpipe for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, showing the braided stainless flex section, V-band flange and welded bracket tab on polished steel.
Polished 2.5-inch connector pipe from a catless K04 downpipe kit for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, with a welded O2 sensor bung and stepped flared outlet.
Turbo end of a catless K04 downpipe for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, CNC-machined chrome flange with bolt holes and a welded O2 sensor bung capped by a hex plug.
Two stainless V-band clamps included with a catless K04 downpipe pair for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, with tightening bolts for quick 3-inch to 2.5-inch exhaust joints.
SPELAB catless K04 downpipe pair kit for 1997-2005 Audi S4 B5, A6 and Allroad 2.7L BiTurbo, shown with two 3-inch to 2.5-inch stainless pipes, connector tubes, V-band clamps and gaskets beside the branded box.
Pair of catless K04 downpipes for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, mandrel-bent T-304 stainless with flex sections, laid out with two perforated gaskets and V-band clamps.
Complete catless K04 downpipe set for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, two mirror-polished 3-inch tapering to 2.5-inch pipes with connector tubes, V-band clamps and gaskets.
Single catless K04 downpipe for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, mirror-polished T-304 stainless with braided flex joint, CNC flange and mounting bracket tab.
Close view of a catless K04 downpipe for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, showing the braided stainless flex section, V-band flange and welded bracket tab on polished steel.
Polished 2.5-inch connector pipe from a catless K04 downpipe kit for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, with a welded O2 sensor bung and stepped flared outlet.
Turbo end of a catless K04 downpipe for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, CNC-machined chrome flange with bolt holes and a welded O2 sensor bung capped by a hex plug.
Two stainless V-band clamps included with a catless K04 downpipe pair for 1997-2005 Audi S4 A6 Allroad 2.7L BiTurbo, with tightening bolts for quick 3-inch to 2.5-inch exhaust joints.

Catless Downpipe Exhaust for 1997-2005 K04/RS6 Fits Audi S4 B5 A6/Allroad C5 2.7L BiTurbo 3"-2.5"

$269.00
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Description Installation Guide FAQ Shipping & Returns

This Catless Audi 2.7T K04 downpipe replaces the restrictive factory downpipes and removes the catalytic converter for maximum flow. Engineered for Audi, it’s a direct bolt-on upgrade that delivers stronger mid-range torque, faster turbo spool, and a more aggressive exhaust note.

Who This Is For

1997-2005 Audi S4 B5 / A6 / Allroad C5 with the 2.7L BiTurbo K04 engine (or RS6 K04 turbo upgrade) owners who want maximum exhaust flow and a deep, aggressive exhaust note.

Key Features

  • 3" to 2.5" tapered design for optimal flow through the BiTurbo system
  • Includes 2x V-Band clamps for easy installation and service
  • 16-gauge T-304 stainless steel with mandrel bends
  • TIG-welded joints and CNC machine flange
  • Chrome-plated flanges for corrosion resistance

Product Specifications

  • Engine: Audi 2.7L BiTurbo (K04 / RS6 K04 upgrade)
  • Pipe Diameter: 3" tapering to 2.5" (76mm to 64mm)
  • Wall Thickness: 16 gauge (1.5mm)
  • Material: 16-gauge T-304 Stainless Steel
  • Surface: Mirror Polish
  • Configuration: Catless
  • Flange Type: V-Band (2 V-Band clamps)
  • Certificate: ISO9001:2000
  • Weight: 9.90 kg (9900 g)

What's Included

  • 2x 3" to 2.5" upper section
  • 2x 2.5" pipes
  • 2x V-Band clamps
  • 2x Gaskets

Check Before Choosing

  • Engine match: Designed for the 2.7L BiTurbo (B5 S4 / C5 A6/Allroad) and K04-upgraded RS6 builds. Verify your specific turbo setup.
  • Tune required: Yes — a Stage 2+ tune is required to clear CEL and realize the full power gain.
  • K04 vs RS6 K04: K04 (factory) and RS6 K04 (aftermarket upgrade) turbos have similar downpipe flange geometry. Verifies with support.
  • Street legality: No — off-road / race use only.

Vehicle Fitment

Compatible vehicles: Audi A6, Audi Allroad, and Audi S4 B5 (1997–2005).

Year Make Model Engine Chassis
1997 Audi A6 / Allroad C5 2.7L BiTurbo C5
1998 Audi A6 / Allroad C5 2.7L BiTurbo C5
1999 Audi A6 / Allroad C5 2.7L BiTurbo C5
2000 Audi A6 / Allroad C5 2.7L BiTurbo C5
2001 Audi A6 / Allroad C5 2.7L BiTurbo C5
2002 Audi A6 / Allroad C5 2.7L BiTurbo C5
2003 Audi A6 / Allroad C5 2.7L BiTurbo C5
2004 Audi A6 / Allroad C5 2.7L BiTurbo C5
2005 Audi A6 / Allroad C5 2.7L BiTurbo C5
2000 Audi S4 B5 2.7L BiTurbo B5
2001 Audi S4 B5 2.7L BiTurbo B5
2002 Audi S4 B5 2.7L BiTurbo B5