how to check for a bad catalytic converter on my Toyota RAV4 XA50 (2019-2024)?

Solution

1. Preparation

• Gather tools and parts needed for testing and potential replacement.
• Tools Required: OBD-II scanner, pressure gauge, infrared thermometer, multimeter, jack and jack stands.
• Ensure the vehicle is on a flat surface and the engine is cool before starting.

2. Perform Exhaust Flow Test

• Step 1: Locate the exhaust manifold and install the pressure gauge.
• Step 2: Start the engine and allow it to reach operating temperature.
• Step 3: Observe the gauge reading; normal back pressure should not exceed 1.5 psi at idle and 3.5 psi at 2500 RPM.
• Step 4: If pressure is higher, the catalytic converter may be clogged.

3. Temperature Test

• Step 1: Use an infrared thermometer to measure the temperature at the inlet of the catalytic converter.
• Step 2: Measure the temperature at the outlet of the catalytic converter.
• Step 3: A difference of more than 100°F indicates that the converter may be working inefficiently or is blocked.

4. Oxygen Sensor Inspection

• Step 1: Locate the upstream and downstream oxygen sensors attached to the exhaust system.
• Step 2: Use a multimeter to check the voltage output of both sensors while the engine is running.
• Step 3: The upstream sensor should fluctuate between 0.1 to 0.9 volts, while the downstream sensor should show a steady reading. If the downstream sensor mimics the upstream sensor, it may indicate converter failure.

5. Replacement (if necessary)

• Step 1: If the catalytic converter is confirmed faulty, disconnect the negative battery terminal.
• Step 2: Raise the vehicle and secure it with jack stands.
• Step 3: Remove any heat shields and exhaust components as needed to access the catalytic converter.
• Step 4: Unbolt the old catalytic converter from the exhaust system and remove it.
• Step 5: Install the new catalytic converter, ensuring all gaskets are replaced and bolts are torqued to manufacturer specifications.