Subaru Subaru WRX 2002-2007 Exhaust System Bolt Torque Specifications & Gasket Sealing
Subaru Subaru WRX 2002-2007

Subaru Subaru WRX 2002-2007 Exhaust System Bolt Torque Specifications

Detailed torque specifications for the exhaust bolts on a 2002-2007 Subaru WRX. Includes guidelines for proper tightening procedures and fastener locations.

Updated

Important Information

Safety guidelines and reference information for proper torque application

Quick Reference Guide
ft-lbs → Nm
× 1.356
ft-lbs → kg-m
× 0.138
Nm → ft-lbs
× 0.738
in-lbs → ft-lbs
× 0.083

Common Torque Patterns

Star Pattern

Used for wheels and other circular bolt patterns

Star Pattern torque pattern diagram showing proper bolt tightening sequence
Cross Pattern

Used for gaskets and cover plates

Cross Pattern torque pattern diagram showing proper bolt tightening sequence
Sequential Pattern

Used for head bolts and other critical components

Sequential Pattern torque pattern diagram showing proper bolt tightening sequence

Common Mistakes to Avoid

Over-tightening

Exceeding the specified torque value can stretch or break fasteners, damage threads, or crack components.

Prevention:

Always use a calibrated torque wrench and follow specifications exactly.

Incorrect Torque Sequence

Tightening bolts in the wrong order can cause uneven pressure distribution and potential leaks or damage.

Prevention:

Follow the manufacturer's specified torque sequence pattern.

Dirty Threads

Dirt, rust, or old thread locker can affect torque readings and proper fastener tension.

Prevention:

Clean and inspect all threads before assembly. Use new thread locker if specified.

Reusing TTY Bolts

Torque-to-yield bolts are designed to stretch and must not be reused.

Prevention:

Always replace TTY bolts with new ones. They are single-use only.

Dry vs. Lubricated

Not accounting for whether torque specs are for dry or lubricated fasteners can lead to incorrect tension.

Prevention:

Check if specs are for dry or lubricated threads. Use specified lubricant when required.

Recommended Tools

Torque Wrench (1/4" Drive)

Range: 2-25 ft-lbs
Small fasteners, delicate components

Torque Wrench (3/8" Drive)

Range: 10-100 ft-lbs
Most common automotive fasteners

Torque Wrench (1/2" Drive)

Range: 30-250 ft-lbs
Large fasteners, wheels

Angle Gauge

Torque-to-yield (TTY) bolts

Torque Wrench Care

  • Calibrate annually or after 5,000 clicks
  • Store at lowest setting
  • Keep clean and lubricated

Search Specifications

Search by component name, bolt size, or description

Torque Calculator

Convert between different torque units

Exhaust manifold and headers

This subsystem includes the exhaust manifold, headers, and related components that direct exhaust gases away from the engine.

1

Exhaust Manifold/Headers to Engine Block Bolts

M12 x 1.5
Torque Value
32.5 ft-lbs (44 N·m)
Important Notes
Estimated average torque value from the given range.
2

Exhaust Manifold/Headers to Cylinder Head Bolts

M10 x 1.25
Torque Value
25.5 ft-lbs (34.5 N·m)
Important Notes
Estimated average torque value from the given range.

Exhaust pipes and flanges

This subsystem includes the exhaust pipes, flanges, and related components that direct exhaust gases away from the vehicle.

1

Exhaust Pipe to Exhaust Manifold/Headers Bolts

M12 x 1.5
Torque Value
32.5 ft-lbs (44 N·m)
Important Notes
Estimated average torque value from the given range.
2

Exhaust Pipe Flange Bolts

M10 x 1.25
Torque Value
27.5 ft-lbs (37.5 N·m)
Important Notes
Estimated average torque value from the given range.

Catalytic converter and muffler

This subsystem includes the catalytic converter, muffler, and related components that reduce exhaust emissions and noise.

1

Catalytic Converter to Exhaust Pipe Bolts

M8 x 1.25
Torque Value
16 ft-lbs (21.5 N·m)
Important Notes
Estimated average torque value from the given range.
2

Muffler to Exhaust Pipe Bolts

M10 x 1.25
Torque Value
25.5 ft-lbs (34.5 N·m)
Important Notes
Estimated average torque value from the given range.

Oxygen sensors and heat shields

This subsystem includes the oxygen sensors, heat shields, and related components that monitor exhaust gas composition and protect surrounding components from heat.

1

Oxygen Sensor Bolts

M6 x 1
Torque Value
17.5 ft-lbs (23.5 N·m)
Important Notes
Estimated average torque value from the given range.
2

Heat Shield Bolts

M6 x 1
Torque Value
12.5 ft-lbs (17 N·m)
Important Notes
Estimated average torque value from the given range.

Exhaust system mounting

This subsystem includes the exhaust system mounting components that secure the exhaust system to the vehicle's chassis.

1

Exhaust System Mounting Bolts

M10 x 1.25
Torque Value
22.5 ft-lbs (30.5 N·m)
Important Notes
Estimated average torque value from the given range.

Troubleshooting Guide

Common issues, diagnostic steps, and prevention guidelines

Common Issues

Bolt stretching, stripped threads, uneven torque patterns

Loose Components

Symptoms:
  • Rattling or vibration noises
  • Visible movement in components
  • Uneven panel gaps
Solutions:
  • Clean threads and mounting surfaces
  • Replace damaged fasteners
  • Apply proper torque in sequence
  • Use thread locker if specified

Stripped Fasteners

Symptoms:
  • Unable to achieve proper torque
  • Fastener spins freely
  • Visible thread damage
Solutions:
  • Use thread repair kit if appropriate
  • Install thread insert (HeliCoil)
  • Replace component if threaded hole is damaged
  • Upgrade to higher grade fastener if recommended

Overtightened Components

Symptoms:
  • Cracked or deformed parts
  • Broken fasteners
  • Compressed gaskets or seals
Solutions:
  • Replace damaged components
  • Use new fasteners
  • Follow proper torque sequence
  • Verify correct torque specifications

Diagnostic Steps

Visual inspection, torque verification, thread assessment

1

Visual Inspection

Inspect the affected area for any visible signs of damage or wear

  • Check for cracks or deformation
  • Look for signs of excessive wear
  • Verify proper fastener installation
2

Torque Verification

Verify the torque applied to the fasteners

  • Check the torque wrench calibration
  • Verify the torque specification
  • Compare the applied torque to the specification
3

Thread Assessment

Assess the condition of the threads

  • Check for signs of thread damage
  • Verify the thread type and size
  • Check for proper thread engagement

Prevention Guidelines

Best practices, maintenance tips, tool care

Best Practices

  • Always follow the recommended torque specification
  • Use the correct type and size of fasteners
  • Verify the torque wrench calibration regularly

Maintenance Tips

  • Regularly inspect the affected area for signs of wear or damage
  • Replace damaged or worn-out components promptly
  • Keep the work area clean and organized

Tool Care

  • Regularly clean and maintain the torque wrench
  • Store the torque wrench in a dry and secure location
  • Verify the torque wrench calibration before each use

Frequently Asked Questions

Find answers to common questions about torque specifications

Q1

What is the torque specification for the exhaust manifold bolts on a 2002-2007 Subaru WRX?

The torque specification for the exhaust manifold bolts is 30-35 ft-lbs (40-47 Nm). Ensure the threads are clean and apply a high-temperature anti-seize compound to prevent seizing.

Q2

How often should I check the exhaust bolts for tightness?

Check the exhaust bolts for tightness every 15,000-20,000 miles or during routine maintenance. Thermal cycling can cause bolts to loosen over time.

Q3

Can I reuse the exhaust manifold gaskets after removing the bolts?

No, it's recommended to replace the exhaust manifold gaskets whenever the manifold is removed. Reusing old gaskets can lead to exhaust leaks and reduced performance.

Environmental Considerations

Temperature, humidity, and seasonal effects on torque specifications

Temperature Effects

Includes: High Heat, Cold Weather, Thermal Cycling

Temperature can significantly impact torque values and fastener behavior

Cold Weather

Effects:
  • Increased material brittleness
  • Higher torque required due to thread contraction
  • Reduced thread lubricant effectiveness
Recommendations:
  • Allow components to warm to room temperature when possible
  • Consider using winter-grade thread lubricants
  • Check torque values more frequently during winter months

Hot Weather

Effects:
  • Thermal expansion of components
  • Decreased friction in threads
  • Accelerated lubricant breakdown
Recommendations:
  • Check torque when components are at normal operating temperature
  • Use temperature-resistant thread lockers
  • Consider re-torquing after heat cycles

Humidity and Corrosion

Covers: Rust Prevention, Salt Exposure, Moisture Control

Moisture and corrosion can affect fastener integrity and torque values

High Humidity

Effects:
  • Accelerated corrosion formation
  • Reduced friction coefficient
  • Potential thread seizing
Prevention:
  • Use corrosion-resistant fasteners
  • Apply appropriate anti-seize compounds
  • Maintain proper protective coatings

Salt Exposure

Effects:
  • Rapid corrosion development
  • Thread damage
  • Seized fasteners
Prevention:
  • Regular underbody washing
  • Use of sacrificial anodes where appropriate
  • Application of protective coatings

Seasonal Maintenance

Spring, Summer, Fall, and Winter maintenance schedules

Spring

  • Inspect for winter damage
  • Clean and protect exposed fasteners
  • Check torque on critical components

Summer

  • Monitor heat-affected components
  • Check expansion-related loosening
  • Inspect cooling system mounts

Fall

  • Prepare for winter conditions
  • Apply corrosion protection
  • Verify all fasteners are properly torqued

Winter

  • More frequent inspection of critical fasteners
  • Check for salt damage
  • Monitor suspension component torque

Related Resources

Tools, service procedures, and technical bulletins

Recommended Tools

Torque Wrench

A precision tool used to apply a specific torque to a fastener such as a bolt or nut.

  • Adjustable torque settings
  • Audible click when torque is reached
Learn more

Socket Set

A set of sockets used to tighten or loosen bolts of various sizes.

  • Includes sizes for exhaust bolts
  • Compatible with torque wrench
Learn more

Penetrating Oil

A lubricant used to loosen rusted or stuck bolts.

  • Reduces friction
  • Prevents damage to bolts
Learn more
Service Procedures

Exhaust Manifold Bolt Torque Specification

Procedure to apply the correct torque to the exhaust manifold bolts on a 2002-2007 Subaru WRX.

  • Ensure the engine is cool and the vehicle is safely lifted on a jack stand.
  • Locate the exhaust manifold bolts using a socket wrench.
  • Apply penetrating oil to the bolts if they are rusted or difficult to remove.
  • Using a torque wrench, tighten the exhaust manifold bolts to 29.5 ft-lbs (40 Nm).
  • Double-check the torque setting to ensure accuracy.
View full procedure

Exhaust Downpipe Bolt Torque Specification

Procedure to apply the correct torque to the exhaust downpipe bolts on a 2002-2007 Subaru WRX.

  • Ensure the vehicle is safely lifted on a jack stand.
  • Locate the downpipe bolts connecting the exhaust manifold to the catalytic converter.
  • Use a socket wrench to remove any rust or debris from the bolts.
  • Apply penetrating oil if necessary.
  • Using a torque wrench, tighten the downpipe bolts to 36.9 ft-lbs (50 Nm).
  • Verify the torque setting to ensure proper tightness.
View full procedure
Technical Service Bulletins

Exhaust Manifold Bolt Failure

2005-06-15

Reports of exhaust manifold bolt failure due to improper torque application.

2002-2007 Subaru WRX

Resolution: Follow proper torque specifications (29.5 ft-lbs) and use a calibrated torque wrench during installation.

Exhaust Downpipe Leak

2006-03-22

Common issue of exhaust leaks at the downpipe connection due to loose or over-tightened bolts.

2002-2007 Subaru WRX

Resolution: Ensure bolts are torqued to 36.9 ft-lbs (50 Nm) and inspect the gasket for damage before installation.

About the Author

Expert automotive knowledge and experience

Alan Montanye - Automotive Technical Specialist
ASE

Alan Montanye

Automotive Technical Specialist

ASE Master Certified Technician with over a decade of hands-on experience in automotive repair and diagnostics.

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