how to fix P0420 code in Honda Accord 9th Generation (2013-2017)

Solution

1. Preparation

• Gather tools and parts.
• Disconnect the battery to prevent electrical issues during repairs.
• Raise the vehicle using a jack and secure it with jack stands.

2. Inspect and Replace Oxygen Sensors

1. Remove the Upstream Oxygen Sensor:

   • Locate the upstream oxygen sensor (typically before the catalytic converter).
   • Use an O2 sensor socket to unscrew and remove the sensor.

2. Install the New Upstream Oxygen Sensor:

   • Apply anti-seize compound to the threads of the new sensor.
   • Install the new sensor and tighten it to the manufacturer’s specifications (usually around 30 ft-lbs).

3. Repeat for the Downstream Oxygen Sensor:

   • Locate and remove the downstream oxygen sensor in the same manner.
   • Install a new downstream oxygen sensor with anti-seize compound and tighten to specifications.

3. Inspect and Replace Catalytic Converter (if needed)

1. Remove the Exhaust Components:

   • If the catalytic converter needs replacement, disconnect the exhaust pipes leading to and from the converter (use a socket set).
   • Unbolt the catalytic converter from its mounting points.

2. Install the New Catalytic Converter:

   • Position the new catalytic converter into place.
   • Reattach exhaust pipes and bolts, ensuring connections are snug and leak-free (consult manufacturer’s torque specifications).

4. Reset the Check Engine Light

• Reconnect the battery.
• Use an OBD-II scanner to clear the P0420 code from the vehicle’s computer.