Confused, Annoyed And Irritated

Jordo!

If the H-pipe diameters are larger, it may make "whooshing" or rasping sounds.

If you are hearing a raw rasp/rattle on decel in particular, around 2 - 2.5 K, it's the ART pipes. I don't know about break in -- they are supposed to be designed with Helmholtz resonators, or so I thought...

If the rattle is random, try adding some thick rubber washers to dampen some of the vibrations (heat resistant stuff, like for high quality intake tubing, cut into sections) where the pipes may be making contact with the cross member, as someone suggested.

Good luck! Getting the VQ motor to NOT sound like a spluttering pick up truck is no mean feat...

I had very modest rasp with resonated (standard) TP's plus the (poorly quality, frankly) Nismo S-tune Weldina -- switched to OBX wider Y and got woohsing -- I've heard of similar issues on some H and X's as well -- went back to the Weldina, which suffered several leaks over time...

You might swap out the H pipe for a take-off Nismo one, or see about adding additional resonators somewhere in the mix -- there's a thread or two on the subject.

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