It is very difficult to determine what your problem is considering other garages have failed to cure your problem,if the fault is still on a code reader after repair and deletion then the fault must be present,if the fault is in relation to the throttle flap it does not mean the fault lies solely with that item and could be related to various items which work in conjunction with the intake system ie. throttle pedal,air flow meter etc,sometimes these faults are a nightmare to sort out and I think it will take someone with good knowledge of these motors and the correct computer for a look at live data and even possibly a wiring diagram with the correct voltages etc required at the various sensors/connectors,also the wiring looms in and around the engine compartment for chaffing/broken wires etc,good luck
cdc
June 2014