I've cleaned out the TB but again I can't be sure it is working 100% as it is 'drive by wire' electronic!! Am I correct in thinking that idle is controlled by the PCM and just slightly opens the throttle, so in theory a faulty electronic TB could shut off completely closing the throttle? would this cause my issue? Could I bench test it?



The engine side of the TB was caked in carbon deposits, I've cleaned it up best I can.



Is that little channel to the left of the TB anything to do with idle control? there is a matching one on the intake manifold.