Exhaust system
Exhaust system parts — catalysts, DPF, silencers, pipes and lambda sensors
The Exhaust System category covers components that route and clean exhaust gases from the manifold to the tailpipe. You will find catalytic converters, diesel particulate filters (DPF/FAP), silencers (front, centre, rear), exhaust pipes, flex connectors, clamps, lambda sensors and exhaust-gas temperature sensors.
Modern diesel engines feature complex aftertreatment systems (DOC + DPF + SCR) whose correct operation requires functional sensors and clear filtration elements. A blocked DPF restricts engine power and triggers limp mode — regular regeneration and timely service are essential.
Frequently asked questions
How does DPF regeneration work?
Passive regeneration occurs automatically during sustained higher-speed driving — exhaust temperature exceeds 600 C and soot burns off naturally. Active regeneration is triggered by the ECU, which injects extra fuel to raise the temperature. If both fail — a forced service regeneration is required.
What causes the DPF to become blocked?
Frequent short-distance driving (engine never reaches regeneration temperature), a faulty exhaust-gas temperature sensor, a leaking injector (excess soot), use of the wrong engine oil (not Low-SAPS) or a damaged differential-pressure sensor.
How often should the lambda sensor be replaced?
Lambda sensors have no fixed replacement interval — they are changed on failure (fault codes P0130-P0167). Service life is 80,000-150,000 km. A worn sensor causes increased fuel consumption, higher emissions and potential DPF regeneration failure.