Quote:
Originally Posted by Todd/AWE
We've confirmed these cats to be the latest 200 cell HJS units by the serial tag. The chance that they are actually damaged is very, very slim. UPS would have had to run over them with a truck to damage them internally during shipping, and there would be obvious external signs of that.  Plus, no cat codes or CEL are present.
We have installed countless of these cats in house, in combination with all sorts of other headers and mufflers, and have yet to hear what may be referred to as a rattling noise during operation. However, anything is possible given how freer flowing our cats are and how that may "excite" some of the baffling in the OE mufflers, producing a momentary harmonic. Without an actual sound bite, we are doing our best to help.
Nexus, we're not looking to upsell you, but if you are indeed looking to upgrade your mufflers, let's see what we can do for you. |
I agree with you; that's exactly what's happening. When I was running the same setup as Nexus, there was an almighty resonance inside the standard cans when used with your cats and it pipes-up (please excuse the pun!) at 3-4000rpm. It sounds as if the insides of the mufflers have disintegrated and are rattling around in the cans!
When I had this issue, replacing the Porsche cans with your mufflers put everything back to how it should be, proving your cats were fine. I've also had the complete standard system back on the car again briefly since (to go to the local stealer) and that proved there was nothing wrong with my standard cans either.
I doubt Nexus has an issue with his cats or Porsche cans - as you correctly say, it's just the much more open nature of your cats that interacts oddly with the standard Porsche items.