I've just had the cubby box out this morning to get at the transfer box linkage from above and have realised that the EGR ECU is disconnected and I'm assuming it has been since I bought it (about 18 months and 30,000 miles). Does it need to be conected up or is it ok just left disconnected? the EGR is already blanked off so isn't doing anything but just wasn't sure if ECU was still important? :-k