Simply put, no it is not possible to perform the Tweaking glitch in any game other than any Generation IV game.
The game's engines are built differently; and the Generation IV engine happens to be the one that allows you to do Tweaking.
The Diamond and Pearl engines were older than those of Platinum and Heart Gold and Soul Silver, which is why its more common in Diamond and Pearl.
- 01.26.2012 7:27p