Has anyone had a problem when I.e coming down a hill on overrun and within 3 or so seconds the engine takes a funny turn and decides to turn off the injectors. I'm thinking this is to protect the cats. I dont have cats anyone know how to get over this. Im wondering if it's a variable on the ecu.

I always have to rev the car before a junction/lights after overrun to continue normal idle.

my bmws been doing this too. slow down for a junction/lights, foot on the clutch, stop, engines dead.
its an air leak after the air flow meter on mine, still trying to sort it properly. hose clamp should do it

I had something similar with the focus, it was an air leak (split breather hose)