i searched n i couldnt get a straight answer so here it goes ... i just installed spipe back with oe-rs system .... everything seems fine but wen i revd the engine i hear sum kind of rasp sound .. i dont have a header ... i guess kinda like buzzing ... does that mean theres a leak?

 

is the exhaust hitting any part of the car?

 

Check ur connection again between the s-pipe and mid pipe...

I installed headers but still have my stock exhaust and I think the noise I get is similar to what you are talkin about....
You might want to try and get some sort of sealant like copper gasket, something like that (I have some in the car if you want the exact name)...and try loosening the mid pipe putting some in there and re tighten it....it should take some of that noise away...

Sorry if this doesnt help at all....lol

 

if you put the stock bar that is held in with 4 bolts on (that is holding stock exhaust up from falling, take it off and the new exhaut wont hit it causing the annoying rattleing sound.

 

I have the same setup, and luckily don't have any buzzing problem. However, buzzing is often a symptom of an exhaust leak. Get yourself 3 feet of garden hose or similar, put one end in your ear and the other near the different connection points. You should be able to pick out the spot where your leak is.