Seaside Auto Repair

Mon - Fri: 8:00 AM - 5:00 PM

Why would I need a Catalytic Converter?

Why would I need a Catalytic Converter?

At Wayside Garage, we recently had a Toyota Tacoma come in with a check engine light on. Jonathan and I dove into the diagnostics to figure out what was going on. Here's a rundown of our process and findings, which might help you understand what goes into diagnosing and fixing such issues.

Understanding the Problem

The check engine light was triggered by a P0430 code, which points to a problem with the catalytic converter, specifically on bank two. This code indicates that the catalytic converter isn't operating efficiently.

Diagnostic Process

1. Pulling Codes: We started by pulling the diagnostic trouble codes (DTC) using our scanner.
2. Driving and Monitoring: We then drove the vehicle with the scanner connected while monitoring the upstream and downstream oxygen sensors. These sensors help us understand how well the catalytic converter is performing.

What We Found

- Oxygen Sensor Behavior: In this case, the rear (downstream) oxygen sensor was mimicking the behavior of the front (upstream) oxygen sensor. This indicated that the catalytic converter wasn't working properly because it wasn't sufficiently cleaning the exhaust gases.

Why Catalytic Converters Fail

While catalytic converters are designed to last a long time, they can fail due to various reasons, including:

- Engine Misfires: Unburned fuel can enter the catalytic converter and cause damage.
- Oil Consumption: Burning oil can clog the catalytic converter.
- Sensor Issues: Faulty oxygen sensors can cause the engine to run rich or lean, leading to catalytic converter failure.
- Lack of Maintenance: Neglecting regular maintenance like tune-ups can also contribute to premature failure.

Preventative Measures

Regular maintenance can help prevent catalytic converter issues:

- Oxygen Sensor Replacement: It's a good idea to replace oxygen sensors around every 50,000 miles. These sensors play a crucial role in helping the engine run efficiently and can prevent catalytic converter problems.
- Regular Tune-Ups: Keeping up with tune-ups and addressing any engine performance issues promptly can save your catalytic converter and improve fuel economy.

Get Help from ASE Certified Technicians

If you have a check engine light on or think it might be time to replace your oxygen sensors, come see our ASE-certified technicians at Wayside Garage in Seaside, California. We're here to help you keep your vehicle running smoothly.

Contact Us

- Phone: 831-899-2425
- Website:

Don't forget to like and subscribe to our channel for more tech tips and updates!


Wayside Garage is committed to ensuring effective communication and digital accessibility to all users. We are continually improving the user experience for everyone, and apply the relevant accessibility standards to achieve these goals. We welcome your feedback. Please call Wayside Garage (831) 899-2425 if you have any issues in accessing any area of our website.