Hi all, i bouth a 330i 2000 model last year, hel of a vechicle up until now. every now and again i loose a lot of power, it comes and go's. Took her to bmw,no error codes, so i went for second op, still no error codes. Thinking of chucking the cats, can this be done ? if that doesn't fix the problem, what else can it be ?

Getting rid of your cats will definitely through some codes without some configuring. Cannot offer any help on the intermitent power-loss though.

change the spark plugs?
oil?