What is an EGR?

EGR stands for Exhaust Gas Recirculation. It is an emissions system that routes a controlled amount of exhaust gas back into the intake, so it is re-burnt during combustion. The main purpose is to reduce NOx (nitrogen oxides) by lowering peak combustion temperatures.

Is EGR bad for performance?

Not always. While many people associate EGR with reduced performance, it can have a positive effect by lowering combustion temperatures. On many modern diesel engines, EGR also plays a role in the wider emissions strategy and can influence how often the DPF needs to regenerate.

In some setups, disabling EGR can lead to more frequent DPF regenerations, which can have a negative impact on fuel economy.

Why do EGR systems fail?

Because the EGR system carries sooty exhaust gases, it is prone to carbon buildup. Over time this can restrict flow or cause valves to stick. When that happens, the ECU may detect an EGR flow or control fault, often leading to warning lights and restricted performance.

What does the EGR solution do?

An EGR solution removes EGR related faults and calibrates the ECU so it no longer expects EGR flow from the system.

For best results, we generally recommend blanking the EGR mechanically as well. If an EGR valve is stuck open, it can negatively affect drivability even if the ECU is no longer monitoring it.