Audi Audi S4 2003-2008

Audi Audi S4 2003-2008 Exhaust Specifications

Detailed technical specifications and documentation for the 2003-2008 Audi S4 exhaust system, including exhaust manifold, catalytic converters, mufflers, and tailpipes. Ideal for repair, maintenance, and upgrades.

Updated Oct 24, 2023

Overview Specifications

Comprehensive description of the exhaust specifications for the 2003-2008 Audi S4, including key features, measurements, and technical details. This section covers the exhaust system's design, materials, and performance characteristics, ensuring accurate maintenance and repair.

How to Use

Use the search function to locate specific exhaust specifications by entering keywords such as 'catalytic converter,' 'muffler,' or 'exhaust diameter.'

Navigate through the exhaust documentation sections using the table of contents or by scrolling through the major sections: Exhaust System Overview, Catalytic Converter, Muffler and Resonator, and Exhaust Tips.

Key Specifications

Exhaust Diameter

70 mm (2.75 inches)

Catalytic Converter Lifespan

160,000 km (100,000 miles)

Muffler Weight

8.5 kg (18.7 lbs)

Exhaust Tip Diameter

90 mm (3.54 inches)

Total Exhaust System Weight

32 kg (70.5 lbs)

Available Specifications

Exhaust System Overview

This section provides a detailed breakdown of the Audi S4's exhaust system, including its layout, materials, and key components.

General Layout

Dual exhaust system with two separate pathways for each bank of the V8 engine
Stainless steel construction for durability and corrosion resistance
Total system length: 4.2 meters (13.8 feet)
Exhaust diameter: 70 mm (2.75 inches)
Designed for optimal backpressure to enhance engine performance

Materials and Construction

Primary material: 304-grade stainless steel
Heat-resistant coatings applied to critical components
Weight of the complete exhaust system: 32 kg (70.5 lbs)
Welded joints for maximum durability
Precision-engineered bends for optimal flow

Note: The stainless steel construction ensures longevity, especially in harsh weather conditions.

Catalytic Converter

This section covers the catalytic converter's specifications, including its design, efficiency, and emissions compliance.

Design and Function

Dual catalytic converters, one for each exhaust bank
Ceramic honeycomb substrate with platinum and rhodium coatings
Operating temperature range: 400°C to 800°C (752°F to 1472°F)
Emissions compliance: Euro 4 standards
Flow rate: 450 CFM (cubic feet per minute)

Maintenance and Replacement

Expected lifespan: 160,000 km (100,000 miles)
Replacement cost: Approximately $800 per unit
Oxygen sensor integration for real-time emissions monitoring
Heat shield included for thermal protection
Bolted connections for easy replacement

Note: Regular inspection of the catalytic converter is recommended to ensure optimal performance and emissions compliance.

Muffler and Resonator

This section details the muffler and resonator components, including their design, sound dampening, and performance impact.

Muffler Specifications

Dual-chamber design for effective noise reduction
Internal baffles tuned for a sporty exhaust note
Dimensions: 600 mm x 300 mm x 200 mm (23.6 in x 11.8 in x 7.9 in)
Weight: 8.5 kg (18.7 lbs)
Inlet and outlet diameter: 70 mm (2.75 inches)

Resonator Function

Located between the catalytic converter and muffler
Reduces drone and high-frequency exhaust noise
Dimensions: 400 mm x 200 mm x 150 mm (15.7 in x 7.9 in x 5.9 in)
Weight: 4.2 kg (9.3 lbs)
Constructed from aluminized steel for heat resistance

Note: The resonator is critical for achieving the Audi S4's signature exhaust tone.

Exhaust Tips

This section covers the exhaust tips, including their design, materials, and aesthetic features.

Design and Finish

Dual oval-shaped exhaust tips
Polished stainless steel finish
Diameter: 90 mm (3.54 inches)
Length: 150 mm (5.9 inches)
Integrated heat shields for safety

Installation and Compatibility

Direct bolt-on installation
Compatible with aftermarket exhaust systems
Weight: 1.2 kg (2.6 lbs) per tip
Designed to complement the rear bumper design
No welding required for replacement

Note: The exhaust tips are designed to enhance the vehicle's sporty appearance while maintaining functionality.

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Component Specifications

General Specifications

Material: Stainless steel

System Type: Dual exhaust with cross-pipe

Configuration: Rear-mounted mufflers with quad tips

Emission Compliance: Euro 4

Part Number: 8E0253600A

Exhaust Manifold

Material: Cast iron

Bolt Torque: 25 Nm + 90°

Gasket Part Number: 06B253039A

Heat Shield Material: Aluminized steel

Heat Shield Part Number: 8E0253117B

Catalytic Converters

Type: Dual catalytic converters

Material: Ceramic substrate with platinum coating

Efficiency: >95%

Part Number: 8E0254605C

Temperature Range: 400°C to 800°C

Replacement interval: 120,000 miles

Resonators

Type: Center-mounted resonators

Material: Stainless steel

Part Number: 8E0252605D

Diameter: 60 mm

Length: 400 mm

Mufflers

Type: Rear-mounted dual mufflers

Material: Stainless steel

Part Number: 8E0253605E

Diameter: 70 mm

Length: 600 mm

Sound Level: 85 dB at 3000 RPM

Exhaust Pipes

Material: Stainless steel

Diameter: 65 mm

Wall Thickness: 1.5 mm

Flex Pipe Part Number: 8E0253115F

Clamp Part Number: 8E0253115G

Oxygen Sensors

Type: Wideband lambda sensors

Part Number: 06A906262A

Location: Pre-catalytic and post-catalytic

Operating Temperature: -40°C to 900°C

Replacement interval: 100,000 miles

Exhaust Mounts

Material: Rubber with steel inserts

Part Number: 8E0253115H

Quantity: 4

Torque Spec: 22 Nm

Replacement interval: Inspect every 30,000 miles

Exhaust Tips

Material: Polished stainless steel

Diameter: 90 mm

Length: 150 mm

Part Number: 8E0253115J

Finish: Chrome-plated

Operational Parameters

Max Exhaust Gas Temperature: 950°C

Back Pressure Limit: 0.5 bar

Idle Emission Levels: CO: <0.5%
HC: <100 ppm
NOx: <200 ppm

Warranty Coverage: 8 years or 80,000 miles

Service Information Service

Detailed service requirements and schedules for the exhaust system

30,000

Inspect exhaust mounts for wear
Check for exhaust leaks
Inspect oxygen sensor operation

Replace any damaged or worn components immediately

60,000

Inspect catalytic converter efficiency
Check resonator and muffler condition
Verify exhaust back pressure

Use Audi-approved diagnostic tools for testing

100,000

Replace oxygen sensors
Inspect and clean exhaust tips
Check exhaust system alignment

Follow Audi-recommended procedures for sensor replacement

Frequently Asked Questions

Find answers to common questions about torque specifications

What is the diameter of the exhaust pipes on the 2003-2008 Audi S4?

The 2003-2008 Audi S4 features dual exhaust pipes with a diameter of 2.25 inches (57 mm) for the standard exhaust system. Aftermarket or performance exhaust systems may vary.

What type of catalytic converter is used in the Audi S4 exhaust system?

The 2003-2008 Audi S4 is equipped with a high-flow, stainless steel catalytic converter designed to meet emissions standards. It is integrated into the downpipe and has a diameter of 2.5 inches (63.5 mm).

Can I install an aftermarket exhaust system without voiding my warranty?

Installing an aftermarket exhaust system may void your warranty if it causes damage to other components or violates Audi's warranty terms. Always consult your dealer or warranty documentation before making modifications.

What is the recommended torque specification for exhaust manifold bolts?

The exhaust manifold bolts on the 2003-2008 Audi S4 should be torqued to 18-22 lb-ft (25-30 Nm) in a crisscross pattern to ensure even pressure and prevent leaks.

How often should the exhaust system be inspected?

The exhaust system should be inspected every 15,000 miles (24,000 km) or during routine maintenance. Check for leaks, corrosion, and damage to hangers, gaskets, and pipes.

What is the material used in the Audi S4 exhaust system?

The factory exhaust system is made of stainless steel, which provides durability and resistance to corrosion. Performance exhaust systems may use titanium or other lightweight materials.

Are there any specific safety precautions when working on the exhaust system?

Always allow the exhaust system to cool before performing any work. Use proper lifting equipment and safety gear. Avoid working in enclosed spaces to prevent carbon monoxide poisoning.

Factory Service Resources

Access official service manuals, technical documents, and repair guides. These resources provide detailed procedures, specifications, and diagrams directly from the manufacturer.

Audi S4 Exhaust System Service Manual

Coming Soon

Official Audi service manual detailing exhaust system components, removal, and installation procedures.

Performance Exhaust Upgrade Guide

Coming Soon

Comprehensive guide to upgrading the Audi S4 exhaust system, including compatibility and performance gains.

Exhaust System Maintenance Checklist

Coming Soon

Step-by-step checklist for inspecting and maintaining the Audi S4 exhaust system.

Audi Genuine Parts Catalog

Coming Soon

Catalog of genuine Audi exhaust components, including part numbers and specifications.

Exhaust System Troubleshooting Guide

Coming Soon

Guide to diagnosing and resolving common exhaust system issues on the Audi S4.

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