how to fix P0420 code on Ford Explorer Fifth Generation (2011-2019)

Ford Explorer Fifth Generation (2011-2019)

Error Codes

2-4 hours

Time

medium

Difficulty

medium

Severity

Error Code: P0420

3 min read

547 words

Problem Statement

Learn how to diagnose and fix P0420 exhaust system issue in Ford Explorer (2011-2019). Step-by-step guide with diagnostic procedures and repair instructions.

Error Code

P0420

Affected Component

Exhaust System

Estimated Time

2-4 hours

⚠️ Safety Warnings

Important safety information - read before proceeding

•Disconnect the battery before working on electrical systems.
•Allow the exhaust system to cool before inspection or repair.

Symptoms

•Check engine light illuminated
•Decreased fuel efficiency
•Poor engine performance or power loss
•Unusual exhaust smells (e.g., rotten egg odor)
•Increased emissions during inspection

Diagnostic Steps

1
Scan the vehicle's onboard diagnostic system with an OBD-II scanner to confirm the P0420 code and check for any additional codes.
2
Inspect the exhaust system for visible leaks or damage, particularly around the catalytic converter.
3
Measure the voltage output of the upstream and downstream oxygen sensors using a multimeter to check their functionality.
4
Perform a visual inspection of the catalytic converter for any signs of physical damage or excessive carbon buildup.
5
Check for proper air-fuel mixture using a fuel pressure gauge and ensure the engine is running smoothly.
6
Inspect the exhaust for any restrictions, such as clogs or blockages.

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

•OBD-II scanner
•Multimeter
•O2 sensor socket
•Wrench set
•Socket set
•Fuel pressure gauge
•Exhaust pipe cutter

Parts Required

•Upstream oxygen sensor
•Downstream oxygen sensor
•Catalytic converter (if needed)
•Exhaust gaskets

Related Faults

Share this solution

Comments

No comments yet

Be the first to share your thoughts

Back to Generation

Diagnostic Steps

1
Scan the vehicle's onboard diagnostic system with an OBD-II scanner to confirm the P0420 code and check for any additional codes.
2
Inspect the exhaust system for visible leaks or damage, particularly around the catalytic converter.
3
Measure the voltage output of the upstream and downstream oxygen sensors using a multimeter to check their functionality.
4
Perform a visual inspection of the catalytic converter for any signs of physical damage or excessive carbon buildup.
5
Check for proper air-fuel mixture using a fuel pressure gauge and ensure the engine is running smoothly.
6
Inspect the exhaust for any restrictions, such as clogs or blockages.

Solution

1. Preparation

Gather tools and parts required for the repair.
Disconnect the battery to ensure safety while working on electrical components.
Raise the vehicle using a jack and secure it with jack stands.

2. Inspect and Replace Oxygen Sensors

Tools Required: O2 sensor socket, wrench set, multimeter
Locate the upstream and downstream oxygen sensors.
Disconnect the electrical connectors for both sensors.
Using the O2 sensor socket, remove the upstream sensor first, followed by the downstream sensor.
Install the new oxygen sensors by reversing the removal process, ensuring they are securely tightened to manufacturer specifications.

3. Inspect and Replace Catalytic Converter (if needed)

Tools Required: Socket set, exhaust pipe cutter, gaskets
If inspection indicates the catalytic converter is damaged, proceed to remove it.
Remove any bolts or clamps securing the catalytic converter to the exhaust system using a socket set.
Cut the exhaust pipe if necessary, ensuring a clean cut for proper fitment of the new converter.
Install the new catalytic converter, using new gaskets and ensuring all connections are tight and leak-free.

4. Reset the Check Engine Light

Reconnect the battery.
Use the OBD-II scanner to clear the P0420 code from the vehicle's computer.
Start the engine and allow it to run for a few minutes.