Originally Posted by NewKidinTown

Some posts here talk about the matrix being inert. That only means it does not function as an emission device, i.e., it does not trap particulates. Inert is not synonymous with non-obstructive. If the matrix impedes flow, it most likely hinders performance. Common sense and one look at the filters should tell us that that is the case with U.S. matrices.

Originally Posted by TXshaggy

I think we’re thinking way too hard here.

Inert, non inert, unmonitored, etc.

Porsche has stated that the non monitored GPFs exhibit the same metrics (flow and sound attenuation) as the monitored.

This allows Porsche to build one standard for the world.

Originally Posted by TXshaggy

I think we’re thinking way too hard here.

Inert, non inert, unmonitored, etc.

Porsche has stated that the non monitored GPFs exhibit the same metrics (flow and sound attenuation) as the monitored.

This allows Porsche to build one standard for the world.

Originally Posted by unclemat

Not so. If it's non-inert i.e. it does remove some particulates, that it makes a difference when it comes to removal.

In other words, is removing the element only about changing the flow/sound or is it making emissions difference?

Originally Posted by Bill Mitchell

Here is a pic of the matrix that came out of the set of OEM GPF's I installed on my '21 GTS 4.0. Sound is a little bit louder, but not much.