[Lucky]

Thanks ian.

Answered my own question too. Ive been driving it around for a couple of weeks now with the flap delete done and to me, despite a bit more sound generally at low speed, it wasnt popping and banging like it did when giving it the beans. Tonight, i changed it back and plugged the flap back in.

Normal mode - a bit quieter outside and a lot quieter inside (no droan)
Sport mode - popping and banging all over the place again.

So, it seems to work better with the flap doing its thing.