Keon,
whn is ur last engine service? this time whn u change engine oil, see is there any small fine metal pcs. whahahahaha.
anyway i dun think the problem with your engine la. the problem is YOU...!!! you already get too used with ur car power until now u dun feel anything liao. thats why u complain.... this is the very 1st stage of going to BOT. VERY NORMAL SIGN. whahahahaha