EGR
When exhaust gas returns into the engine
Modern diesel engines use exhaust gas recirculation (EGR). Part of the exhaust gas is taken from the exhaust tract in a controlled way and fed back into the intake air. The main goal is to reduce the formation of nitrogen oxides (NOx).
The engine can no longer breathe freely
When intake passages are narrowed by deposits, the intended air flow suffers. Possible results are poor throttle response, power loss, uneven running, EGR faults and deviations in air mass and boost pressure.
Exhaust gas contains soot and combustion residue. Once back in the intake tract it can combine with oil mist from the crankcase ventilation and build up on the EGR valve, intake manifold, swirl flaps and inlet ports. Over high mileage this can turn into heavy carbon build-up.
DPF
The diesel particulate filter
The DPF traps a large share of the soot particles. To keep it from filling up, the vehicle raises exhaust temperature during regeneration and burns off most of the accumulated soot.
Do not simply replace parts
Analyse the cause and the measured values first. A DPF problem can be the consequence of another fault rather than its actual origin.
Frequent short trips, repeatedly interrupted regenerations, technical defects or unfavourable operating conditions can increase the soot load. If exhaust back pressure rises, the engine management monitors the condition through temperature and differential pressure data.
SCR · AdBlue · NOx
A complex chain
Many modern diesels dose AdBlue into the exhaust flow. Inside the SCR catalyst nitrogen oxides are chemically reduced. NOx sensors before and/or after the catalyst report to the control unit how the system is performing.
If a component fails or delivers implausible values, this can trigger warnings, reduced engine power or follow-on reactions. That is why we never read fault codes in isolation, but analyse measured values and their relationships.
Exhaust systems & software solutions
Technically competent. Legally clear.
MC Performance Cars operates professional diagnostic and programming equipment for modern engine and control-unit systems, including ECU strategies, EGR control, DPF, SCR/AdBlue and NOx sensors.
For vehicles used on public roads, emission-relevant systems must comply with applicable legal and type-approval requirements. We only carry out modifications or deactivations where they are legally permissible for the specific application, for example in expressly permitted motorsport, development or off-road use.