Peugeot 307 Depollution System Faulty: (100% Solutions!)


Peugeot 307 Depollution System Faulty

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Driving a car like the Peugeot 307, it’s quite common to encounter a warning on your dashboard that reads “depollution system faulty.”

But what are the common causes for Peugeot 307 Depollution System Faulty? In essence, this error message usually indicates that there could be an issue with your exhaust system or other components affecting emissions.

From clogged diesel particulate filters and malfunctioning EGR valves to damaged oxygen sensors or fuel injectors – all these can contribute to the depollution system fault in a Peugeot 307.

This article will delve into each of these potential culprits in more detail.

This message indicates an issue with your car’s emissions control system. It could be caused by various factors, including: Faulty oxygen sensor, Faulty exhaust gas recirculation (EGR) valve, Problematic catalytic converter, Faulty diesel particulate filter (DPF) and Faulty glow plugs (diesel engines only).

What is the Depollution System in Peugeot 307?

Peugeot 307 Depollution System Faulty

The depollution system in a Peugeot 307 is an integral part of the vehicle’s exhaust system. It’s designed to capture, store, and dispose of harmful pollutants that are generated during engine operation. Here’s what you need to know:

The depollution system includes several key components:

  • Catalytic Converter: Transforms harmful gases into less toxic substances.
  • Diesel Particulate Filter (DPF): Captures soot particles from diesel emissions.
  • Oxygen Sensors: Monitor oxygen levels for optimal combustion.

When functioning correctly, the depollution system reduces environmental impact by decreasing:

  • Nitrogen Oxides (NOx)
  • Carbon Monoxide (CO)
  • Hydrocarbons (HC)
Key ComponentFunction
Catalytic ConverterConverts harmful gases into less harmful ones
Diesel Particulate FilterTraps soot particles from diesel emissions
Oxygen SensorsEnsures optimal combustion by monitoring oxygen levels


  1. Regular maintenance can help ensure your car’s depollution system operates efficiently.
  2. Ignoring warning signs or error messages related to the depollution system may result in more serious damage over time.

In conclusion, understanding how your Peugeot 307’s depollution system works will keep your vehicle running smoothly while minimizing its environmental footprint!

Common Symptoms of a Peugeot 307 Depollution System Faulty:

If your Peugeot 307’s depollution system starts acting up, there are some common signs to help pinpoint the problem.

  • Check Engine Light: The most obvious sign is the illumination of the check engine light on your dashboard.
  • Decreased Fuel Efficiency: If you’re filling up more often than usual, it could be due to a faulty depollution system.
  • Performance Issues: You may notice that your car isn’t accelerating as well as it used to or struggles when climbing hills.
Check Engine LightThis will illuminate on your dashboard
Decreased Fuel EfficiencyMore frequent trips to the pump
Performance IssuesPoor acceleration and difficulty with inclines

Remember these symptoms don’t always mean a faulty depollution system, they can also point towards other issues within your vehicle. Always consult with a professional mechanic for accurate diagnosis and repair.

Causes of a Depollution System Fault in Peugeot 307:

Peugeot 307 Depollution System Faulty

Depollution system faults in the Peugeot 307 can be traced back to several common causes:

  • Faulty EGR Valve: The Exhaust Gas Recirculation (EGR) valve helps reduce the car’s emissions. However, this part may get clogged or malfunction, leading to depollution system fault warnings.
  • Damaged Oxygen Sensors: These sensors measure oxygen levels in your vehicle’s exhaust gas. Malfunctioning or damaged ones cause errors in emission control, prompting a depollution fault.
  • Blocked DPF: Diesel Particulate Filter (DPF) captures and stores exhaust soot. A blocked or faulty one can cause depollution issues.

Here’s a quick comparison table for these common causes:

Faulty EGR ValveCan get clogged/malfunction resulting into warning signals
Damaged Oxygen SensorsErrors due to malfunction/damage affect emission control
Blocked DPFCaptures and stores exhaust soot; blockage/faults lead to problems

With each of these potential culprits:

  1. Check and clean the EGR valve regularly.
  2. Regularly inspect oxygen sensors for damage.
  3. Ensure that the DPF isn’t blocked by performing periodic maintenance checks.

Regular maintenance is key as it allows early detection of any faults hence preventing costly repairs later on.

Watch this video for more in-depth detail:

1. Faulty Oxygen Sensor: A Possible Cause:

The oxygen sensor, an important component of your Peugeot 307’s depollution system, might be responsible for the “Depollution System Faulty” message. It measures the level of oxygen in your car’s exhaust gases.

Here are some common signs that indicate a faulty sensor:

Why does it matter?

When this sensor fails, it can lead to:

  1. Poor fuel efficiency – Your vehicle may consume more fuel than necessary.
  2. Increased emissions (hence the depollution warning) – More pollutants will be released into the environment.

Common Causes

Here’s a breakdown of common reasons behind a failing oxygen sensor in a table format:

Contaminated or Failed SensorThis could be due to oil ash accumulation or usage over time causing it not to respond correctly
Wiring IssuesDamaged wires connecting the sensor can cause false readings
Burned Out Heater CircuitThe heated circuit within sensors can burn out and malfunction

If you notice any symptoms listed above, get your car checked by a professional technician immediately.

2. Clogged Catalytic Converter: Another Potential Culprit:

The catalytic converter plays a critical role in the Peugeot 307 depollution system. It’s responsible for converting harmful gases into less toxic substances before they’re released from your car’s exhaust.

If it gets clogged, you might see the dreaded “depollution system faulty” warning light on your dashboard.

Here are some reasons why this happens:

  • Excessive Oil Consumption: High oil consumption can lead to residue build-up and eventual clogging of the catalytic converter.
  • Bad Quality Fuel: Prolonged use of substandard fuel results in carbon deposits that can block the catalytic converter.

And these are symptoms to look out for:

  1. Reduced engine performance
  2. Lower fuel efficiency
  3. A foul smell from exhaust

For diagnosis and potential solutions, refer to the table below:

-Step 1--Check oil levels regularly; high consumption could indicate an issue.-
-Step 2--Use quality fuel always; avoid cheap, low-quality alternatives.-
-Step 3--Get a professional examination if there is reduced performance or unusual smells.-

Remember, ignoring this problem may lead to expensive repairs down the line!

3. Issues with the EGR Valve: Contributing to Depollution Problems:

The Exhaust Gas Recirculation (EGR) valve plays a crucial role in controlling pollution emissions from your Peugeot 307. When it malfunctions, you’re likely to encounter “Depollution System Faulty” alerts.

Common issues include:

  • Clogging: Over time, soot accumulates and clogs the EGR valve.
  • Failure: The EGR valve can fail due to wear and tear or electrical faults.
  • Sticking open/closed: Sometimes, the EGR may get stuck in an open or closed position.

These problems contribute significantly towards depollution system failure. Let’s look at each issue more closely.


  1. Occurs due to long-term build-up of soot
  2. Causes reduced engine performance
  3. Leads to increased exhaust emissions


  • Often results from faulty wiring
  • May also occur because of mechanical wear and tear
  • Results in excessive NOx emission levels

Sticking Open/Closed:

  1. Generally happens when there is poor maintenance
  2. Affects combustion process negatively if stuck closed; increases exhaust emissions if stuck open
CloggingLong-term build-up of sootReduced engine performance & Increased exhaust emissions
FailureFaulty wiring or Mechanical wear and tearExcessive NOx emission levels
Sticking Open/ClosedPoor MaintenanceNegatively affects combustion process if stuck closed; Increases exhaust emissions if stuck open

To avoid these issues, regular servicing of your Peugeot 307 is recommended including checking for signs of damage on the EGR valve.

4. Malfunctioning Mass Airflow Sensor (MAF): How it Affects the System:

The Mass Airflow Sensor (MAF) plays a pivotal role in your Peugeot 307’s depollution system. When it malfunctions, you’re likely to encounter a ‘Depollution System Faulty’ warning. Here’s how a faulty MAF impacts the system:

  • Inaccurate air-fuel mix: The MAF measures the amount of air entering the engine. If malfunctioning, incorrect data gets sent to your car’s computer, causing an improper air-fuel mixture.
  • Poor fuel economy: Since more fuel than needed might be burned due to inaccurate readings from the damaged MAF sensor, this leads to reduced fuel efficiency and increased emissions.
  • Reduced performance: Miscommunication between the MAF and onboard computer can lead to poor acceleration and overall weak performance.

Here are some common symptoms indicating a possible malfunction with your Peugeot 307’s MAF:

Check Engine Light Comes OnThe most obvious sign something is wrong.
Idle Issues or StallingCan indicate that too much or too little fuel is being delivered because of incorrect airflow readings from a bad MAF sensor.

To rectify these issues:

Peugeot 307 Depollution System Faulty
  1. Get an OBD2 scanner: Plug it into your vehicle and read any trouble codes.
  2. Clean up: Sometimes cleaning out dust on sensor wires may fix problems.
  3. Replace if required: If cleaning doesn’t work, consider replacing the part entirely.

Remember! Always consult with professional service before making major changes yourself!

5. Fuel Injector Problems and Their Impact on Depollution Performance:

Fuel injectors play a crucial role in your Peugeot 307’s depollution performance. When they malfunction, it can trigger the ‘Depollution System Faulty’ warning. Here are some common fuel injector issues that may affect the depollution system:

  • Clogged Injectors: Over time, debris and deposits can clog up the fuel injectors, leading to poor fuel combustion and increased emissions.
  • Leaking Injectors: If an injector is leaking, it’ll cause excess fuel to enter into engine parts where it shouldn’t be. This messes with the air-fuel ratio causing inefficient combustion which contributes to pollution.
  • Worn Out Injectors: Like any other part of your car, injectors wear out over time. A worn-out injector will not spray the correct amount of fuel into the cylinder creating an imbalance in air/fuel mixture which potentially could increase emission levels.
IssueSymptomsPotential Impact
Clogged InjectorsPoor acceleration, reduced MPG (miles per gallon), rough idling.Increases harmful emissions due to incomplete combustion of fuel.
Leaking InjectorsSmell of gasoline, hard starting or black smoke from exhaust.Excess unburnt gas ends up in exhaust increasing pollution level.
Worn Out InjectorsEngine misfires or decrease in power and performance.Disrupts optimal air/fuel mixture promoting higher emissions.

Regular maintenance is key here:

  1. Get regular engine check-ups
  2. Use quality gasoline
  3. Regularly replace old injectors

Remember: Preventive measures always save you from bigger headaches down the road!

6. Electrical Wiring and Connection Issues: Troubleshooting Tips:

When it comes to the Peugeot 307 depollution system, electrical wiring and connection issues can often be the culprit. Here are some troubleshooting tips:

  • Visual Inspection: Start by visually inspecting all wires connected to your depollution system. Look for breaks, burns or signs of wear; these could indicate a problem.
  • Use a Multimeter: A multimeter can test if there’s an electric current running through your wires. If there isn’t, you may have found the issue.
  • Check Connectors and Terminals: Faulty connections can also cause problems with your depollution system. Ensure that connectors aren’t corroded or loose.

Here is a simple guide on what to look out for while examining wiring and connections:

ComponentPotential Issue
WiresBreaks, burns or signs of wear
ConnectorsCorrosion or looseness
TerminalsLoose contacts

Remember these steps when dealing with electrical faults:

  1. Begin with visual inspection.
  2. Use a multimeter for testing.
  3. Examine connectors & terminals closely.
  4. Repair any identified problem areas immediately.

Proper maintenance will ensure smoother operation – remember prevention is always better than cure!

Regular Maintenance for Preventing Depollution System Faults:

Keeping up with regular maintenance can help prevent a “Depollution System Faulty” error on your Peugeot 307. Here’s what you need to do:

1. Regular Oil Changes

2. Monitor Fuel Quality

  • Always use clean, high-quality fuel.
  • Low-quality fuel can lead to excessive emission production which strains the depollution system.

3. Replace Air Filters

  • Dirty air filters affect engine performance and increase pollutant emissions.
When To ReplaceWhy It’s Important
Every 12,000 -15,000 milesEnsure optimal air/fuel mix

4. Maintain Exhaust System

  • A faulty exhaust system can trigger depollution errors.
  • Check regularly for leaks and damage.

In addition, consider having your vehicle inspected by a professional if it has been involved in an accident or if you notice any changes in its performance or fuel efficiency.

Conclusion and final thoughts

The Peugeot 307’s depollution system is a crucial part of the vehicle, designed to minimize environmental impact while maintaining optimal performance.

When it becomes faulty, you might experience poor fuel economy, increased emissions, and compromised engine performance.

Common causes include issues with the catalytic converter, oxygen sensors or fuel injectors.

Stay vigilant for warning signs like unusual exhaust smoke or a check engine light that won’t go off. Regular servicing helps prevent these faults before they escalate into more serious problems.

Trust in professional help when dealing with intricate systems such as this one – your car and environment will thank you!

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