I have a 2005 Defender 90 Td5 fitted with exhaust gas recirculation (EGR). I’m thinking of fitting a blanking kit, but I’m unsure what to do with the wires to the modulators. I also want to fit a de-cat pipe – will there be any increase in mpg or bhp?
J Vickers, Llansawel, Dyfed
Before going ahead with this, it’s worth pointing out that the EGR system operates only on light throttle, so don’t expect to notice any performance enhancement. It’s also there for a very good reason – to reduce the amount of nitrogen oxides leaving the exhaust pipe. Reducing nitrous oxide emission is especially important during town driving.
A kit will also include a plain-bore pipe to fit in place of the EGR valve. This will eliminate any flow restrictions caused by the valve, even when it is open. For your EU3-compliant engine, the kit will also contain blanking plates for the EGR cooler, which is integral with the EGR gas pipe across the front of the engine. A plug or cap will be included to blank off the redundant modulator valves, but no electrical disconnection is needed.
Precautions during removal
When the EGR valve is removed, you may see oil and carbon caked inside the air inlet. Like the EGR valve, this restricts airflow. But removing it risks dislodging hard particles that can fall into the manifold and pass through to the engine. It’s best to remove the manifold if you wish to clean it. Replacing the catalytic converter with a plain (de-cat) pipe is unlikely to produce any change in performance or economy. More importantly, changes to the MoT test early this year require that a cat should be present if the vehicle was originally built with one.