ehmm2x....i dunno whether u have the same prob as me or not but...i think almost the same.i would like to clarify again, r u using the stock pipping?im using K&N pod filter attached to stock pipping, it makes cyclone noise as well....and my mechanic says that the idle level is too low.... he told me to ask the toyota mechanic to increase the idle level when i service it but the toyota dude told me that they cant (dunno why). its only making cyclone noise when the engine is cold.but once its warmed up, it'll turn back to normal.im used to the noise now...since it doesnt troubled me so i just leave it as it is.well not sure if this is helpful but just letting u knw, i have the same prob. dunno exactly why...