Depollution System Faulty on Peugeot 307: Causes and How to Fix

If you have recently received a “Depollution System Faulty” message on your Peugeot (307, 308, or 207) dashboard, you are not alone. This is a common issue that many Peugeot owners face, and it can be quite concerning.

The cause of the “depollution system faulty” message on a Peugeot car is likely due to a faulty oxygen sensor, mass airflow sensor, or catalytic converter. To fix the issue, first check the oxygen sensor, mass airflow sensor, and catalytic converter for any signs of damage or dirt buildup. 

If any of these components are damaged or dirty, they should be replaced.

Keep reading for more details about this warning message and how to go about it

What Does “Depollution System Faulty” Mean On Peugeot 307, 308 & 207?

Depollution System Faulty on Peugeot

As mentioned earlier, “Depollution System Faulty” is an error message that can appear on Peugeot’s dashboard. It indicates a problem with the engine’s emission control system, which includes the fuel and exhaust systems. 

Various issues, including a faulty fuel pump, dirty fuel filter, bad ignition coil, faulty spark plugs, or malfunctioning exhaust filter, could trigger the error.

When this error code appears, the engine management light may also turn on, and the car may enter “limp mode,” which reduces power and speed to prevent further damage. 

To diagnose and fix the problem, it’s best to take the car to an expert with experience working on Peugeot 307s and use a fault code reader to identify the specific issue.

Causes of Depollution System Faulty Message on Peugeot 307

There are several possible causes of Depollution System Faulty message on Peugeot 307. Here are some of them:

Faulty Oxygen Sensor

The oxygen sensor measures the amount of oxygen in the exhaust gases and sends this information to the engine control unit (ECU). The ECU uses this information to adjust the air/fuel ratio to ensure efficient combustion. 

A faulty oxygen sensor can cause the ECU to receive incorrect information, resulting in the engine running rich or lean. This can trigger the depollution system faulty message.

Faulty Catalytic Converter

The catalytic converter converts harmful pollutants into less harmful gases before they are emitted from the exhaust pipe.

A faulty catalytic converter can cause an increase in the level of pollutants emitted by the car, triggering the depollution system faulty message.

Faulty EGR Valve

The Exhaust Gas Recirculation (EGR) valve redirects some of the exhaust gases into the engine to reduce emissions.

A faulty EGR valve can cause the engine to run poorly, and the depollution system may detect high levels of pollutants, triggering the error message.

Clogged Particulate Filter

The particulate filter traps soot particles from the exhaust gases and prevent them from being released into the atmosphere.

Over time, the filter can become clogged, reducing its effectiveness. A clogged particulate filter can trigger the depollution system’s faulty message.

Low-Quality Fuel

Using low-quality fuel can cause a build-up of deposits in the engine, affecting its performance and causing it to emit more pollutants. This can trigger the depollution system’s faulty message.

Electrical Issues

Electrical issues such as a faulty coil or a bad spark plug can cause the engine to misfire, affecting its performance, and causing it to emit more pollutants. This can trigger the depollution system faulty message.

What Happens After Receiving the “Depollution System Faulty” Message?

Poor Engine Performance

When the depollution system is faulty, it can lead to poor engine performance. The engine may struggle to start or may stall, especially when idling. There may also be a noticeable power, acceleration, and overall performance decrease.

Reduced Fuel Efficiency

A faulty depollution system can also lead to reduced fuel efficiency. The car may use more fuel than usual, and the driver may have to refill the tank more frequently than before. This can be a costly problem, especially for people who drive long distances frequently.

Strange Engine Noises

The engine may make strange noises when the depollution system is not working correctly. These noises can range from whistling to banging or knocking sounds. The sound may be coming from the exhaust or the engine, which can indicate a serious problem.

How to Fix and Reset “Depollution System Faulty” Message on Peugeot

Here are some steps you can take to fix this issue:

1. Check Oxygen Sensor

A faulty oxygen sensor is a common cause of a depollution system faulty message. The oxygen sensor measures the amount of oxygen in the exhaust, and if it is not working properly, it can cause issues with the engine’s fuel mixture. An expert mechanic can replace a faulty oxygen sensor.

2. Inspect Catalytic Converter

Another potential issue is a clogged or faulty catalytic converter. The catalytic converter converts harmful gases into less harmful ones before they exit the vehicle’s exhaust.

A clogged catalytic converter can lead to poor engine performance and fuel efficiency. A professional mechanic can inspect and replace a faulty catalytic converter.

3. Check EGR Valve

The EGR valve recirculates exhaust gas back into the engine to reduce emissions. If the EGR valve is clogged or not functioning correctly, it can lead to issues with the engine’s performance and fuel efficiency.

A mechanic can inspect and replace a faulty EGR valve.

4. Particulate Filter

Diesel engines are equipped with particulate filters that trap harmful particles from the exhaust.

If this filter becomes clogged, it can lead to poor engine performance and fuel efficiency. A mechanic can inspect and replace a faulty particulate filter.

After addressing the issues that triggered the error code, it should disappear from your dashboard. But if the code is still there, you can reset it to clear it off. You can do this by turning off your vehicle’s ignition, then disconnecting and reconnecting the battery.

If that doesn’t ask your mechanic to reset it using tools like an OBD-II scanner.

Preventing the of “Depollution System Faulty” Message on Your Peugeot

  • Regular Maintenance: Regular maintenance of your Peugeot 307 or 308 is crucial in preventing depollution issues. This includes oil changes, air filter replacement, and fuel filter replacement.
  • Quality Fuel: Always use high-quality fuel to prevent clogging of fuel injectors and fuel filters.
  • Avoid Short Trips: Frequent short trips can cause issues with the exhaust system. To prevent this, try to take longer drives at least once a week.
  • Watch the Engine Light: If you notice the engine management or check engine light come on, don’t ignore it. Have your vehicle checked by an expert as soon as possible.

Final Words

Depollution System Faulty Message on Peugeot a car is a common issue many drivers may experience. If the message appears, take the necessary steps to fix the issue.

As mentioned earlier, common causes of the message include a faulty oxygen sensor, a faulty catalytic converter, or a faulty EGR valve. 

To fix the issue, drivers should check the oxygen sensor, the catalytic converter, and the EGR valve. If the problem persists, it is best to consult a qualified mechanic and have the car serviced.