aight, well i just installed some DC Sport headers 4-2-1 into my 7th gen i4 accord and im a bit disappointed. i couldnt tell that much of a bhp gain. i reset my ECU and havent drove it since. or maybe the bhp gain is there but i just didnt notice it. now the question that i have is that when i drive i hear a whistleing sound come from where the bottom part of the headers connects to tha cat. is this whistleing sound normal when installing aftermarket headers?