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.
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.
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.
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.