i just installed my aw header... i love the performance and the exhaust note with the TRD exhaust is somewhat ricey to me but many of my friendS like it....
BUT NOW I HEAR A HISSING AND BUZZING SOUND... IM NOT SURE IF ITS COMING FROM THE EXHAUST BECAUSE OF THE NEW HEADER OR ITS A LEAK WHERE THE SPIPE CONNECTS... ALSO IT MIGHT BE THE THROTTLE BODY THAT GOT LOUDER WITHOUT THE MUFFLING HEAT SHIELD....THE BUZZING AND HISSING ONLY COMES WHILE I'M FLOORING IT WHILE DRIVING...THERE'S NO HISSING AT A STOP REVVING.. REPLY BACK SO I DONT DAMAGE MY CAR....

i can't hear mine that much, since my exhaust is hella loud
but if its only hissing when your stomping the gas, from what i remember that was normal....
and the ricey sound is normal with header,sorry

Yeah, I have the AW header and CAI and I get the same hissing. I think its just because there is a increase in airflow, you can actually hear it going through. Hope all is OK.

Nothing really sounds out of place to me. When you add a header to any car you'll get some rasp which could also be call "buzzing". The his is probably the intake like SSH_Motorsport said or maybe a blown out gasket. Just keep and eye on the flanges for black soot (spelling?). If nothing shows up you're fine as far as something beign wrong.

Make sure the donut gasket is in between the s-pipe and the header.. The first time I put mine on I didn't even realize it was there, I had a huge exhaust leak and it sounds very similiar to how you described the problem.

hmmm... never really heard n e hissing or n e thing like that. I have k&n on mine thats the only hising i hear

Its rasp just like every other header produces with an axleback exhaust..install a larger resonator and it will be gone...try searching as there are probably 5 threads on page one of the NA forum with resonator info

thanx for the quick replies...

yeah its rasp or another case of the killer bees.