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?

 

you probally have an exhaust leak, did you replace all the gaskets?

 

You won't notice a ton of Hp out of just headers. And the guy above is probly right, you may have a leak.

 

when i installed my exhaust i felt a definite horse power gain. im not a newbie and i know i aint gonna get like 20 bhp. but i expected atleast to feel it a little bit. and i had a shop to it for me cuz i didnt feel like bothering with the installation. so i dont know what they did. its a performance shop so im guessing they know what theyre doing.

 

its a leak through your gasket, my friend installed nismo headers on his 240 and he got a whistling noise too, then he went back under and saw the gasket wasnt really keepin the two exhaust pieces together tight, he bought a thicker gasket and it got better.

 

try intake and full exhaust...update thread.

 

i think you have an exhaust leak

 

ok so i was running it again in the freeway and this time i did notice somewhat of a horsepower gain. my friend said the whistleing is not a leak cuz he said his brothers 240sx had a leak on the headers and he said my car sounds nothing like his brothers car when it had the leak. he said thats just the noise the headers make. the noise i think comes from where it connects to the cat.