EGR & 02 Sensors- Carbon Cleaning

Why does the EGR valve get dirty?

The EGR valve is designed to cool exhaust gas by burning exhaust for a second time within the intake system. This results in the reduction of nitrogen oxide emissions. Recirculation of the exhaust leads to a gradual accumulation of carbon particles inside the inlet.


These deposits eventually develop into a black layer of soot, which can lead to various engine problems and even engine failure.
The short-term benefits of the EGR valve lead to a faster saturation rate inside the engine. Soot forms where the exhaust passes into the intake, and even within the valve itself, causing various problems. Fuel injectors, which are delicate and expensive components of the engine, may become partially clogged. As for the EGR valve, soot and grime may prevent it from properly opening and closing. If it becomes stuck in the closed position, it will lose all function.


The vehicle will continue to run properly, however it will emit nitrogen oxides at levels beyond the threshold of what is legally tolerated according to area regulations. On the other hand, if the EGR valve becomes stuck in an open position, the engine will become saturated at an even faster rate. Over time, the vehicle will lose acceleration power and certain symptoms will manifest, such as persistent stalling.

1 - The role of the Oxygen sensor

The o2 sensor (oxygen sensor) is located within the exhaust system, upstream of the catalytic converter.
Its role is to inform the ECU of the oxygen content of the burned gases that result from combustion. The o2 sensor helps to ensure that the amount of fuel injected into the cylinders for the air-fuel ratio is at an ideal level.
The o2 sensor ensures low fuel consumption as well as reduced pollutants emitted from the engine. It is therefore an important component to help pass vehicle inspection.
The latest standards of emissions require the presence of a second lambda probe, located after the catalytic converter in order to determine its effectiveness.



2 - Why replace a Oxygen Sensor?

A faulty oxygen sensor has the direct consequence of disrupting the engine air-fuel balance. This leads to an increase in pollutants emitted by the engine, as well as causing the engine to stutter and consequently fuel consumption to increase.



3 - When does the Oxygen Sensor need to be replaced?
The lifespan of an Oxygen Sensor is 160,000 km on average, as long as it is not shortened by engine malfunction.
Unburned oil due to engine misfire may contaminate the probe irreversibly. Exhaust leaks also damage the Oxygen Sensor, leading to an intake of air, which can cause a dangerous increase in temperature.
To ensure the maximum lifespan of the Oxygen Sensor, it is necessary to perform strict engine maintenance (spark plugs, air filter, etc).

Several signs that your Oxygen Sensor needs to be replaced:
-       If the engine check light turns on while the vehicle is being driven.
-       The engine stutters and suffers from a lack of acceleration power.