how to check for a faulty catalytic converter on my Toyota Highlander Fourth Generation (2020-presen...

Solution

1. Preparation

• Gather necessary tools and parts.
• Ensure the vehicle is parked on a level surface and the engine is cool.
• Disconnect the negative battery terminal to prevent any electrical issues.

2. Inspect and Test the Catalytic Converter

a. Visual Inspection

• Use a flashlight to inspect the catalytic converter for cracks, dents, or rust.
• Look for any noticeable signs of leakage.

b. Temperature Test

• Start the engine and allow it to reach operating temperature.
• Use a pyrometer to measure the exhaust gas temperature at the inlet and outlet of the catalytic converter.
• The outlet temperature should be approximately 100-200°F higher than the inlet.
• If the temperature difference is less than this range, the converter may be clogged or failing.

c. Backpressure Test

• Locate the oxygen sensor in front of the catalytic converter and remove it.
• Insert a pressure gauge into the sensor port.
• Start the engine and observe the gauge reading. A reading above 1.5 psi at idle indicates backpressure issues, suggesting a failing converter.

3. Replacement (if necessary)

• If the catalytic converter is determined to be faulty, proceed with replacement.
• Remove the exhaust bolts securing the catalytic converter using a socket set.
• Detach any hangers holding the converter in place.
• Install the new catalytic converter in reverse order of removal, ensuring all bolts are torqued to manufacturer specifications (typically around 30-40 ft-lbs).
• Reinstall the oxygen sensor and reconnect the negative battery terminal.