Exhaust blowing- leakage?

[drem914]

I have a 2001 Boxster that was doing the same thing. First thought it was the heat shields and had the shop clip those off on the secondary cats. Very common to remove the shields. That removed some of the noise, as a lot of gravel had gotten up into the shield area, but that was not the culprit. The likelyhood is that you have a cat converter going bad. Not bad enough to make the CEL go off, but enough that when it heats up it rattles. I replaced all of mine just yesterday with some others that I got used with low miles and the rattle is completely gone. you did not say how many miles you have on the car but if you are getting up in the mileage over 60K, it is very possible that that is wher the rattle is from.

[dangerousdferrari]

Thanks for your reply,

The noise can't really be described as a rattling which was being caused with the heatshield. That noise definitly went away when it was stripped, so I'm thinking that's not the problem.
Its hard to describe the noise but its a spluttery 'clicking' that only occurs unders acceleration. When crusing and when idle - even under some harsh revs, the exhaust sounds fine so it seems to only be apparent under the pressure of acceleration.
Further research seems to be pointing me towards the manifold(?) or as you do mention, the Cat.

Can anyone share anymore thoughts on that?

Thanks,

[Gent]

I just went in to a local muffler shop with my 2k because I was concerned about a rattle that only occurred with light throttle at low speed on a rough road (cruising the Stanley Park causeway with cc set at 40 kph in 2nd).

They checked it out, and informed me the same thing that Drem said about the cats. They start playing the Marraccas when they get hot and worn.