Need your help s2k onwers,
I have installed aftermarket exhaust (Exoticspeed) on my 2005 S2000.
It is somewhat loud but it has very deep and low tone which I like.
Also my butt dyno says quicker acceleration.

But I am hearing some sort of metal rattling between 3-4k rpm range from the rear.
I think vibration created by low exhaust tone is causing this.
It might be coming from the trunk or right behind the seats.
Its really annoying and bothering me ever since.
Does anyone have same issue? Anyone know possible areas where it might be coming from?
Thanks all.

 

if its coming from the trunk I would put my money on the bars that act as springs to push the trunk up... Don't know what they are called exactly but that are black and make an x. They started rattling for me when I installed my exhaust, I just wrapped mine in a towel...

 

i used a hoodie

 

Dont those metal bars have plastic sleeves on them to prevent rattling?
I guess that worked for you then.
Thanks. I will try that first.

 

OEM Cat? High flow cat? Test pipe? All the bolts are good? Is there a mid hanger on your exhaust (one single closes to the cat), and if so did you install it? If you did I'd suggest removing that hanger.

I'm guessing one of three things:

1) Usual problem with cheap exhausts. Metallic rattling at the most resonant ranges (usually 3-4k on our car) are common on cheap quality and construction.
2) Mid hangar is on, and sitting too close to underbody. Most of these exhausts were produced on the AP1 measurements, and while it's not a drastic change, the underbody exhaust 'tunnel' is different (at least on the 06+, not sure about the earlier AP2's).
3) Similar to above; but more in regards to the HFC/TP hitting the tunnel.

 

check the whole pipe. its probably touching the frame. just use different hangers.

 

Mine is a cat-back exhaust with stock cat.
It has mid resonator and a hanger. i will check if any piping is touching anything.
Thanks for your input.

 

if the above suggestions don't work out, check the fuel pump cover. at certain rpms, your exhaust may be causing the cover to rattle.

 

I would bet money it's the fuel pump cover that's rattling.

 

Did you forget to tighten your oxygen sensor? Happend to me one time, rattled like hell untill I tightened it.