Error code p0420 Toyota, Ford and other cars

2024 Author: Erin Ralphs | [email protected]. Last modified: 2024-02-19 11:42

We live in a world that keeps up with the times. Computer technology at the end of the last century did not pass by the automotive industry. The first car with an on-board diagnostic system was introduced by Volkswagen back in 1968.

On-Board Diagnostics

Every driver who owns a modern car knows about the on-board diagnostics system in the car, with which you can find faults in the car. In the literal sense, the car itself determines where and what kind of malfunction it has, and issues a certain diagnostic code to the device, with the help of which the driver or the master determines the malfunction and looks for ways to repair it.

Error p0420

A fairly common diagnostic error code. In the information spaces, and just in everyday life, car owners can hear a lot of information, rumors and advice about this code. Let's look at what it still means, what kind of malfunction it can talk about, whatthere are ways to solve this problem.

What does error code p0420 mean

You see your control light on your dashboard come on. You drive to a car service or perhaps scan the car yourself and find out that the problem is presented in the form of a p0420 code. After displaying the codes, first check that p0420 is the only code. If not, other codes need to be diagnosed as they may cause P0420. The reason for this is that the transducer is the end result of the diagnostics. Basically, if there is a problem with one of the sensors in the engine or the exhaust, it can result in a decrease or increase in the amount of fuel entering the engine.

So we see the code, and if there's nothing other than p0420, it often means that your catalytic system's efficiency is lower than what your oxygen sensors should be measuring. This means that there is a problem with either the catalytic converter, or the oxygen sensors, or both. The purpose of a catalytic converter is to destroy harmful pollutants created during the combustion cycle. By using fine platinum and gold meshes to filter the exhaust gases, the catalytic converter is able to reduce tailpipe emissions. The catalytic converter has two oxygen sensors. One oxygen sensor is located upstream (upstream) of the catalytic converter and the other oxygen sensor is located behind (downstream). If frontThe oxygen sensor is working properly and should fluctuate when the vehicle is at operating temperature and when operating in closed loop. If the downstream oxygen sensor is working properly and there are no problems with the catalytic converter, the reading should remain stable. When the oxygen sensors have readings that are similar to each other, this indicates that the catalytic converter is not working properly. If the rear oxygen sensor voltage decreases and begins to fluctuate like the front oxygen sensor, this means that the oxygen levels are too high and the powertrain control module will display error code P0420.

What causes code p0420?

• Muffler damaged or leaking.
• Exhaust manifold damaged or leaking.
• Damaged exhaust pipes.
• Misfire in the engine.
• Contaminated oil in the catalytic converter.
• Faulty catalytic converter (most common).
• Defective engine coolant temperature sensor.
• Faulty front oxygen sensor.
• Faulty rear oxygen sensor.
• Damaged oxygen sensor wiring.
• Incorrectly connected oxygen sensor wiring.
• Damaged oxygen sensor connectors.
• Leakfuel injector.
• High fuel pressure.
• Using the wrong type of fuel (leaded).

How does a mechanic diagnose code p0420?

• Uses an OBD-II scanner to retrieve trouble codes stored in the PCM.

• Views the current data of the downstream (rear) oxygen sensor. Determines if the oxygen sensor is working properly.
• Diagnoses any other codes that may be causing DTC p0420.
• Repairs misfires, ignition problems and fuel system problems as needed.
• Inspect the rear oxygen sensor for damage and excessive wear.
• Checks for PCM updates if the catalytic converter is faulty. After replacing the catalytic converter, PCM updates will be required.

Common errors when diagnosing code p0420

The most common mistake is to replace the oxygen sensors before completing the diagnostic process. If another component is causing DTC P0420, replacing the oxygen sensors will not fix the problem.

How serious is p0420?

The driver should not experience handling problems if DTC p0420 is present. Apart from the check light being on, the symptoms of this DTC may go unnoticed. However, if the vehicle is operated witherror and do not solve this problem, other components may be subject to serious damage. Since there are no handling problems with p0420, this is not considered serious or dangerous to the driver. However, if the code is not corrected in a timely manner, the catalytic converter may be seriously damaged. Because the catalytic converter is expensive to repair, it is critical that DTC P0420 be diagnosed and repaired as soon as possible.

What repair can fix code p0420?

• Replace muffler and repair leaks.
• Replace exhaust manifold and repair leaks.
• Replace exhaust pipe.
• Replace catalytic converter (most common).
• Replace engine coolant temperature sensor.
• Replace front or rear oxygen sensor.
• Repair or replace damaged wiring to oxygen sensors.
• Repair or replace oxygen sensor connectors.
• Replace or repair fuel injectors that are leaking.
• Diagnose any repair for any misfire problems.
• Diagnose and resolve any other related trouble codes that have been stored by the power management module (PCM).

Cheat error p0420

Very oftenyou can come across a glowing malfunction indicator after refueling your car with low-quality fuel. Error p0420 on the Ford Focus is a fairly common thing, and this model is a frequent guest at a car service with this code. The cause of the appearance is the problem with the catalyst described above, it is solved by searching for the reasons for the inefficient operation of the catalytic converter. There are options for the complete removal of the catalyst, because its high cost does not justify replacement with a new one. But deletion does not solve the problem of error p0420 on the Ford. To make it disappear and the indicator does not bother you, you need to deceive the computer or sensor (lambda probe 2). There is a mechanical, electronic and software way to disable. Mechanically, the sensor is inserted into the manifold with a spacer and a hole in it. The electronic method involves installing a resistor in the signal wiring, which will remove the p0420 code on your Ford. The software method - this is the firmware of the on-board computer system, is the most difficult way, since a competent specialist in this kind of activity is needed. These methods in most cases will help to bypass error p0420 on Ford Focus 2 and Ford Focus 3.

There are also services that manufacture and install flame arresters instead of a catalyst. For example, if we are talking about the Mazda 3 (error p0420 is often found on it), for her the right way to fix this problem is to replace the catalytic converter with a flame arrester. Another way is to install a catalyst emulator. One of the mostpopular - Spider CE2, it is easily connected to the cable to the post-catalyst sensor, and the problem is solved. This method is very often used for error p0420 on Toyota Corolla, because it is quite easy to get to the wires of the lambda probe. Using the emulator does not work in all cases.

In case of error p0420 on Suzuki, drivers prefer to knock out the catalytic converter and flash the car's brains to the Euro-2 standard using chip tuning. On some Suzuki models, using the emulator is useless, the error still appears and leads to all the ensuing consequences. The software firmware method is also used, although, as mentioned above, it is rather complicated.

We will describe a popular method using the example of error p0420 in Subaru. For cars of this brand, there is a special firmware for the control unit, where these errors are disabled and never appear again. This solves the problem with the indicator and the on-board system, but only if it is related to damage or wear of the oxygen and catalyst sensors.

Additional comments to review code p0420

Problems with the ignition system, fuel system, air intake and misfire can damage the catalytic converter if they are not corrected quickly. These components are the most common cause of DTC P0420. In some cars, due to this error, cruise control and the stabilization system stop working. In the CIS countries, problems withcatalyst arise due to the poor quality of our fuel, which is not designed for environmental standards "Euro-3" and higher. Therefore, foreign cars whose catalytic systems are produced using high-quality fuel fail. All the previously described problems with the catalyst occur, and it wears out quickly, respectively, showing us a known error in the diagnostics.

Conclusions

If a mistake bothers you, you don’t want to remove the catalytic converter, strive for the car to comply with environmental standards, then you will have to deal with its repair and prevention. Here are some helpful tips:

1. Special products, such as Catalytic Converter Cleaner, clean the catalytic converter, thereby extending its life.
2. Fuel only at trusted gas stations and high-quality fuel. Otherwise, you will have to replace the catalytic converter, and its cost is quite high.

Cheaper alternatives to prevent the described error are installing emulators and reprogramming the system. These options will not degrade the car's performance, and in some cases even improve it.