You may have recently found your Check Engine light has come on because of an issue with the catalytic converter, or you may have just noticed that there’s an error code stored in your car’s engine control computer indicating that there’s something wrong with the catalytic converter. If so, then you may be wondering what exactly this means and what you should do next to address it. To help you understand this issue in more detail, we put together this guide on catalyst system efficiency below threshold and how it can affect your vehicle.

Introduction

A P0420 code refers to a problem in the catalyst system efficiency below threshold. This can be caused by a number of things, but regardless of the cause, it's important that you take your vehicle to an auto repair shop as soon as possible. If you ignore this issue, your catalytic converter could become so clogged with pollutants that it will no longer function properly and will eventually fail altogether. Here's what you need to know about the problem and how to fix p0420 code: 

1) The catalyst system is designed to reduce emissions by burning up pollutants in the exhaust stream before they escape from the tailpipe into the atmosphere. 2) When the sensor detects an under-performing catalytic converter, there may not be enough time left to fix the problem. 3) It's not uncommon for drivers to ignore these issues until it becomes too late; so don't wait any longer if you have this problem! 4) Take your car or truck to a certified mechanic as soon as possible and get it fixed at their next available opening. 5) Have your fuel injector cleaned or replaced if necessary too. 6) If you're wondering how to fix p0420 code, then follow these steps and have someone qualified perform a diagnostic test on your vehicle today!

What Is the P0420 Code?

If your check engine light is on and your vehicle is operating normally, you're not in any danger. However, it's best to have it fixed as soon as possible. A P0420 code indicates that the efficiency of the catalyst system is below the threshold limit. This could mean a few things: clogged fuel injectors or even a faulty oxygen sensor (which can trigger multiple codes). You'll need to get some diagnostic work done to know for sure and how to fix p0420 code. For example, when testing the O2 sensors they would use something like a smog tester or similar equipment. These are quick and easy tests to diagnose whether you have an issue with your O2 sensors (and how to fix p0420 code) or if there are other issues going on with your car that may require more extensive repair work.

Symptoms of a P0420 Code

Your catalytic converter helps reduce emissions when you’re driving. And this code means that the catalyst efficiency is below the threshold for your vehicle. This is often caused by a defective sensor, exhaust system defects, or aftermarket modifications. An oxygen sensor near the catalytic converter can also cause these catalytic efficiency issues if it’s defective or it detects an incorrect fuel-air ratio. Symptoms include higher fuel consumption and exhaust leaks in the vehicle's area of contamination. The OBDII diagnostic trouble codes P0420 Catalyst System Efficiency Below Threshold Bank 1 is stored in any 1996 to 2000 Honda Accord engine computer with over 240 000 miles (386 204 km) or a 2003-2004 Honda Accord engine with over 149 000 miles (241 365 km).

Causes of a P0420 Code

A P0420 code means that the catalytic converter's efficiency is below the allowable limit. There are many causes of this code, including a faulty catalytic converter or an incorrect air-fuel ratio. Sometimes, a faulty oxygen sensor can cause this error message to appear. The most common cause is a faulty catalytic converter. In order to fix the P0420 code, it may be necessary to replace your catalytic converter or have it repaired. A shop can help you determine which course of action would be best for your car and your budget. If your catalytic converter needs to be replaced, parts vary in price and installation time will vary depending on the make and model of your vehicle. Many shops offer free diagnostic service for customers with p0420 codes in order to diagnose what might need repair.

How to Diagnose and Fix a P0420 Code

If your car's check engine light came on, or you were given a P0420 code, we're here to help. If you want to know how to fix p0420 code, read our diagnosis and fix instructions below.

The Check Engine Light Might Come On with the P0420 Code 

The most common way for the check engine light to come on is by getting a P0420 code from the computer. This might mean that one of your catalytic converters is not working correctly or one has gotten too hot, which causes it to break down over time. The exhaust from a catalytic converter typically has clean emissions because it burns off hydrocarbons before they escape into the atmosphere. But when there isn't enough oxygen in the converter, these materials start building up and clog up the system. To find out how to fix p0420 code once and for all, click here!