how do I check if the catalytic converter is clogged on my Toyota Corolla E140 (2006-2013)

Solution

1. Preparation

• Tools Required: OBD-II scanner, back pressure gauge, infrared thermometer, socket set, jack and jack stands.
• Ensure the vehicle is parked on a flat surface and the engine is cool.
• Disconnect the battery to prevent electrical issues while working.

2. Check Exhaust Back Pressure

1. Locate an O2 sensor or a suitable point in the exhaust system to insert the back pressure gauge.
2. Start the engine and allow it to idle.
3. Insert the gauge into the exhaust system and record the back pressure reading.
   • Normal back pressure should be below 2.5 psi at idle and below 3.5 psi at 2500 RPM.
4. If back pressure is too high, the catalytic converter may be clogged.

3. Temperature Measurement

1. Start the engine and let it reach normal operating temperature.
2. Use the infrared thermometer to measure the exhaust temperature before the catalytic converter.
3. Measure the temperature after the catalytic converter.
   • The temperature after should be significantly higher than the temperature before (at least 100°F difference).
4. If there’s minimal temperature increase, it indicates the catalytic converter may be clogged.

4. Further Inspection or Replacement

1. If diagnostics indicate a clogged catalytic converter, visually inspect it for physical damage.
2. If necessary, replace the catalytic converter following manufacturer specifications.