P0420 Honda Civic: Everything You Need to Know

The Honda Civic is a series of cars manufactured since 1972 by the Hinda automobiles company. If you own one of these cars, you already know how efficient and long-lasting they can be. All you need is to care for the car well through regular maintenance. However, did you know that the P0420 Honda Civic error code is one of the common issues the vehicle might face? Here is an outline of everything you need to know about this error code.

What’s the P0420 Honda Civic Error Code?

The P0420 code can be seen when a Honda Civic is plugged into an OBDII scanner. The code stands for Catalyst System Efficiency Below Threshold. The meaning is the same for all the Honda Civic vehicle models. It means that your car has an issue with the oxygen sensor. A Honda Civic consists of two oxygen sensors after and before the catalytic converter. These sensors measure the level of emissions coming out of the converter. Hence, the code means that your car has an issue with these emissions and can experience engine damage.

Causes of P0420 Honda Civic Error Code

A faulty oxygen sensor is the main cause of the P0420 Honda Civic code. These sensors play an essential role in emissions control and engine management. If faulty, they will record the wrong readings, and your vehicle’s computer will log the P0420 error code. In most cases, these sensors lose their accuracy when the car operates for more than 100000 miles. In such a case, check the car regularly to ensure the sensors are in good condition. Therefore, a new car is less likely to develop this problem.

A faulty catalytic converter is also another cause of the P420 error code. The catalytic convert plays an important role in converting harmful gases from the exhaust chamber to reduce environmental pollution. The section can become clogged over time, and this reduces its efficiency. When this happens, your car will log the P0420 Honda Civic code error. Although the catalytic converter is made to last the life of your vehicle, it can become faulty, thus causing other vehicle problems.

The oxygen sensor wiring can also become faulty, thus causing the P0420 error code. The wiring is prone to damage due to its location near the hot exhaust. When damage occurs, it affects the oxygen sensor’s functioning, thus causing the error.

When the exhaust timing of your Honda Civic is off or misfiring, it affects the gases going to the oxygen sensors. The malfunction would cause your vehicle’s computer to log the P0420 error code.

A noticeable leak from the exhaust would affect the figures read by the oxygen sensor, thus causing the error.

A faulty engine temp sensor can also cause the P0420, especially when the computer doesn’t know the engine’s temp. In such a case, it would keep the fuel mixture in the engine rich, disrupting the oxygen sensor readings. The vehicle would then log the error to depict an issue.

Symptoms of the Honda Civic Error Code

The check engine light is the most common symptom of the P0420 Honda Civic error code. However, this light can be caused by other issues affecting your car. Therefore, you need to have it checked to make the necessary repairs.

A faulty catalytic convertor will affect your vehicle’s mileage. The effect depends on how much cogged the converter is. If the vehicle carries a heavy weight, you will feel like it’s running out of gas. It would also operate normally when carrying a lightweight. The symptom would be similar to that of a bad fuel filter. The exhaust gases would have the smell of sulfur. When you notice such issues, consult an automobile repair shop to have the issue repaired before it causes further damage to your car.

How to Fix the P0420 Honda Civic Error Code

Given that many factors cause this error, it is best to have the car diagnosed to determine the exact cause. The oxygen sensors are the most common cause of the P0420 error; therefore, you should inspect them first, not unless you have an exhaust leak. An exhaust leak can be easily determined by checking under the car. If the cause is a faulty oxygen sensor, it might need a replacement or a simple repair. According to Meineke Resource Center, the wiring might also need to be replaced to facilitate the efficient functioning of the oxygen sensor.

If a faulty catalytic convertor causes the issue, simple repairs or a replacement will correct it. In most cases, the catalytic converter would be clogged. Hence, scrubbing off the clogged substances efficiently delivers its function. Similar repairs are necessary on the engine temp sensor. An experienced mechanic or individual knows how to deal with the misfiring issue which might be causing the P0420 code error.

Cost of Fixing P0420 Honda Civic

It is challenging to outline an exact estimate for correcting this error because various factors cause it. For instance, a clogged catalytic converter would cost you less to repair than an oxygen sensor that needs replacement. The best solution is to have a mechanic diagnose the issue to determine the exact cause and give you a cost estimate.

According to Drivetrain Resource, some repair shops will charge you approximately $75 to $100 for the one hour spent diagnosing your car. The additional charges would depend on the issue that needs correction. The cost would also vary from one auto shop to another. Compare options before settling for a particular repair shop. Ensure that the mechanics have the necessary experience needed to repair your vehicle.

Can P0420 Be Fixed at Home?

When a Hinda Civic experiences various issues, it can cost you a lot to repair. Hence, some ask whether they can repair the P0420 Honda Civic error code at home. The answer to this question will vary depending on an individual’s car experience. These cars come with a manual that is used to repair the damaged parts. However, it would be challenging to make such repairs if you don’t know your way around vehicles.

The best option is to hire an expert because they would prevent you from wasting money and time dealing with the wrong car parts. These professionals will also prevent you from causing further damage to the car as you make the necessary repairs. Mechanics have the necessary experience in diagnosing different car issues. They would also detect other areas that might need repairs soon. Hence, taking your vehicle to an auto shop guarantees that your car will serve you longer without facing further issues.

If not diagnosed on time, the P0420 Honda Civic error can cause major damage to your engine. These damages would cost you more to repair in the future than it would have cost you to diagnose the P0420 error code. Therefore, have your car repaired as soon as you notice the symptoms of this error code.

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James Noah

Ah! Driving your King has no twist when you have zero knowledge! Yes, Noah is here with his core experiences about trucks, cars, suvs and atvs. Working as a cheif editor for Automasterx to make you satisfied with solid data driven post.

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