sorry, im eating sticky toffee pudding. if its a variable geometry turbo (VGT) the ecu will be mapped for the egr valve to work. basically, fuel,timing,boost, air intake are all mapped accordingly. boost pressure is used to determine an egr rate. you could shorten the life of the turbo, and fuel consumption will change. its quite complex mapping these. i had a grande punto sporting multi jet diesel and i was having problems with it and thought about blankin the egr off at one point but decided not to run the risk. i confirmed my suspicians with the chaps at work and they said deffinately not to. (i work building prototype diesel engines for future emmision legislations). Egr IMO is a load of Balls IMO to reduce part of emmisions, but a diesel would run loads better without but current laws force engine manufacturers to reduce emmisions. and this is one way. same as DPF filters. load of balls too. more to go wrong and make your car run ****e,and for what? lower emmisions!