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.
|