FAULTBASE
Error CodesASKCars
© 2026 FAULTBASE
All rights reserved.
v2.0.0 • Production
ContactPrivacyImpressum
What are the common issues with the Highlander’s exhaust system? - Toyota Highlander
Home/Cars/Toyota/Highlander/Fourth Generation (2020-present)/What are the common issues with the Highlander’s exhaust system?

What are the common issues with the Highlander’s exhaust system?

Toyota Highlander Fourth Generation (2020-present)

Error Codes
medium
Difficulty
medium
Severity
Navigation
ProblemSymptomsDiagnosisSolution
ProblemSymptomsDiagnosisSolution
4 min read
797 words

Problem Statement

Explore common issues with the exhaust system of the Toyota Highlander (2020-present), including symptoms, diagnostic steps, and repair instructions.

Affected Component
exhaust system

Symptoms

  • •Loud hissing or tapping noise coming from the engine bay.
  • •Decreased fuel efficiency.
  • •A noticeable rotten egg smell (sulfur).
  • •Check Engine Light may illuminate.
  • •Poor fuel economy.
  • •Rough idling or stalling.
  • •Failed emissions test.
  • •Decreased engine performance and power.
  • •Rattling noise from the catalytic converter.
  • •Visible rust on exhaust components.
  • •Unusual noises (e.g., rattling, popping).
  • •Bad smells from exhaust fumes.

Diagnostic Steps

  1. 1
  2. 2
  3. 3
  4. 4
  5. 5
  6. 6
  7. 7
  8. 8
  9. 9
  10. 10
  11. 11

Solution

💡 Expert Tip

For complex repairs like this, consider taking photos at each step. This helps if you need to reverse a step or consult with a mechanic. Also, keep all removed parts organized - you may need to reference them during reassembly.

Verification

After completing the repair, verify that the issue has been resolved:

  • ✓Test the affected component to ensure it functions correctly
  • ✓Check for any error codes or warning lights
  • ✓Monitor the vehicle for a few days to ensure the issue does not recur

Prevention Tips

To prevent this issue from occurring again:

  • •Follow the manufacturer's recommended maintenance schedule
  • •Address warning signs early before they develop into major issues
  • •Use quality parts and fluids recommended for your vehicle
  • •Keep detailed records of all repairs and maintenance

Tools & Equipment Required

  • •Jack and jack stands or ramps
  • •Hand-held smoke machine
  • •Wrenches and socket set
  • •Safety goggles and gloves
  • •OBD-II scanner
  • •Multimeter
  • •Wiring diagram of the exhaust system and sensors
  • •Infrared thermometer
  • •Rubber mallet

Additional Information

Affected Component
exhaust system
Difficulty
medium
Severity
medium
Tools Required
9 items

Related Faults

Loading...

Share this solution

Comments

Sign in to share your thoughts

Sign In

No comments yet

Be the first to share your thoughts

Back to Generation

Common Issues with the Exhaust System of the Toyota Highlander Fourth Generation (2020-present) (XU70)

The exhaust system of the Toyota Highlander (2020-present) can encounter various issues, each with distinct symptoms and diagnostic steps. Below are common problems, their symptoms, and the steps to diagnose and repair them.

1. Exhaust Leak
Tools Required:
  • Jack and jack stands or ramps
  • Hand-held smoke machine
  • Wrenches and socket set
  • Safety goggles and gloves
Repair Instructions:
  1. Lift the Vehicle: Safely elevate the Highlander using a jack and jack stands.
  2. Inspect Components: Check the exhaust manifold, pipes, and muffler for cracks or rust.
  3. Seal Minor Leaks: Use exhaust tape or putty for small leaks. For larger holes, replace the affected section.
  4. Reassemble: Ensure all connections are tight and secure.
  5. Test Drive: Start the vehicle and ensure the noise is gone and check for any warning lights.
2. Faulty Oxygen Sensors
Tools Required:
  • OBD-II scanner
  • Multimeter
  • Wiring diagram of the exhaust system and sensors
  • Safety goggles and gloves
Repair Instructions:
  1. Locate the Sensors: Identify the upstream (pre-catalytic converter) and downstream (post-catalytic converter) oxygen sensors.
  2. Disconnect the Battery: Before working on electrical components, disconnect the negative terminal of the battery.
  3. Remove Faulty Sensor(s): Use an oxygen sensor socket to unscrew and remove the faulty sensor.
  4. Install New Sensor(s): Apply anti-seize compound on the threads of the new sensor and install it securely.
  5. Reconnect Battery: Reconnect the negative terminal of the battery and clear any fault codes from the OBD-II scanner.
  6. Test Drive: Monitor performance and check for any warning lights.
3. Catalytic Converter Failure
Tools Required:
  • OBD-II scanner
  • Infrared thermometer
  • Wrenches and socket set
  • Safety goggles and gloves
Repair Instructions:
  1. Lift the Vehicle: Safely raise the Highlander on jack stands.
  2. Remove Exhaust Components: Detach the exhaust pipes leading to the catalytic converter.
  3. Replace Catalytic Converter: Unscrew and remove the old catalytic converter and install the new unit.
  4. Reassemble Exhaust System: Reattach all exhaust components securely.
  5. Test Drive: Start the vehicle and ensure proper performance without warning lights.
4. Exhaust System Rust and Corrosion
Tools Required:
  • Jack and jack stands or ramps
  • Rubber mallet
  • Wrenches and socket set
  • Safety goggles and gloves
Repair Instructions:
  1. Lift the Vehicle: Elevate the vehicle using a jack and jack stands.
  2. Remove Affected Components: If rust is extensive, consider removing the affected parts of the exhaust system.
  3. Replace with New Parts: Install new pipes or muffler as necessary.
  4. Protect New Parts: Consider applying high-temperature paint to prevent future rust.
  5. Reassemble and Test: Reattach all components and test for leaks and performance.
Conclusion

Regular maintenance and timely diagnostics are crucial for the exhaust system's health. Addressing symptoms early can prevent more significant issues and ensure optimal vehicle performance. If you are not comfortable performing these repairs, it is advisable to seek assistance from a certified automotive technician.