is it blowing loads of smoke?
un plug the O2 sensor and see if that makes a difference.
also unplug your AFM and see if that makes a difference.
there is an ignition module on the top at back of the cam cover, the big square-ish flat thing with all the wires. that controls the coil packs this could be the issue. if your spark is breaking down then your bov will acctuate.
very VERY slim chance but i could be your throttle position switch too, had a VLT that was cutting out on full throttle coz the TPS was wired in backwards!!! some plonker had put an XF throttle body on there and forgotten to mod the TPS to suit!!!!
also check your spark plugs dude, it does sound spark related to me.