Exhaust blowing- leakage?

[dangerousdferrari]

Hi all,

My '99 Boxster recently had its latest major service and the slight rattling of the exhaust was supposedly fixed by Porsche, at an insane cost for 6 new screws....
The problem came back after around 2 weeks, so it took it back to Porsche and they said the only definitive fix would be to remove the loose heatshield.
3 weeks later, after a problem free MOT and fuel service, the exhaust seems to be blowing a little upon start up. Then, when accelerating, it is making a 'clicking' noise that echoes terribly from any nearby walls or cars on the passenger side (RHD - UK model).
Can anyone tell me if this is leakage from the exhaust as I seem to gather from previous information posted on this forum? Which part of the exhaust could be causing the problem? And could it be Porsche's fault for removing the heatshield? Apologies for sounding naive, or dare is say dumb, but could the fuel service of increased efficiency so much as to have caused the problem?
Any help is much appreciated as I'm reluctant to revisit my local Porsche centre for diagnostics after them trying to fleece me for unnecessary work on my major service - work that incidentally deemed totally unnecessary by an independent dealer.

Thanks for any contribution.

[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.