EGR Delete Cable - Nissan Navara D23/D40 with YD25 engine

The vehicle EGR (Exhaust Gas Recirculation) system reduces engine emissions but has some inherant compromises regarding engine efficiency and reliability. The system works by recirculating exhaust gasses back into the combustion chamber during low engine loads (typically from idle to half throttle) the valve opens and some of the already burned exhaust gases are sent back to the intake to get mixed with fresh air and are combusted for a second time. The combustion temperatures are reduced which in turn reduces the NOx (Nitrogen Oxide) emissions. 

Failure often occurs when the dirty exhaust gasses clog up the valve causing it to stick in the open position, when this happens the engine is starved of oxygen and becomes sluggish and inefficient, in some cases the vehicle can become almost undriveable. The EGR valves can also fail electronically when the internal motor or position sensors fail. Over time the wet burned gases layer themselves on the hot intake ports of the head and build up to significantly block the ports and reduce the engines ability to breathe.