Planet 9

**MarkinHouston** · #1 06-02-2009, 07:52 AM

Greetings all,

First, yes, I did use the search function. And didn't find the answer to this question:

In the quest for a) better and louder sound from the stock PSE and b) eliminating the "power washer" sound at WOT and high rpm, does anyone know what the effect would be of removing the secondary cats from the mufflers?

Judging by that "power washer" sound, there must be some significant restriction in that muffler system somewhere. I recall looking at the photos of the internals (photos now unavailable apparently) which showed a pretty restrictive looking secondary cat. So I wonder if that's where the restriction is.

The PSE looks like it has a fairly straight passage out the tail pipe after the cat, so that makes me think that perhaps removing the cat might be the solution. It won't affect the check engine light. We don't have sniffer tests here in Texas. So I don't see a problem with that.

Now, if those assumptions are true, would it sound better?

Next, how would you remove them?

Get out the Dremel with a zillion little cutting discs and then find someone to weld the thing back together? Can a water jet cutter do it? Would regular welder guys know how to weld it back afterwards?

For that matter, once opened, would the cat just slide out or are we looking at radical catectomy?

Thanks for your thoughts, I do appreciate your time and attention.

- Mark

PS: Yes, I have thought of the Borla as well so I wouldn't ruin a perfectly good PSE, but I do like the switchabilty. It's just not loud enough...

**ruwoodbury** · #2 07-29-2009, 09:05 PM

No thoughts on this out there?
The secondary cats and muffler cases are obviously integrated, but there's also a clamp around the portion that holds the cat. Is it possible to open that up and remove the cats? Or is installing a catback system the only way to get rid of the secondary cats?
BW

**K-Man S** · #3 07-30-2009, 04:10 AM

While anything is possible, I don't think it is really worth the effort it would take to cut and re-weld the factory exhaust to remove the secondary cats vs. an aftermarket catless catback exhaust. The Porsche sports exhaust still has the rear cats, it just changes the muffler routing some and in our exhaust comparison test last year it wasn't all that different from the stock exhaust. I'm sure removing the seconday cats probably would make it a little louder or change the tone, but I don't know if it would be in a good way or not.

Maybe someone will experiment with this, I know someone did back in the old 986 Boxster days and as I recall the removal of the secondary cats was easier on that exhaust but didn't have a big change, so again on the 987 might not be worth the effort.

Tomasz · #4 07-31-2009, 07:51 AM

Just replace the headers with catless set from NHP or FabSpeed. I did that on my stock exhaust. Results in the dyno forum.

harryo2b · #5 08-05-2009, 09:56 AM

I've done it. Bought a spare muffler set for cheap, I assume they would be even cheaper now, and cut and gutted it. Removed everything. (used to have the photos on here but that was long ago)

Also there is a Belgian parts dealer that does custom muffler tuning on the cheap as well for 987 cars. PM me for details about them.

***alan93rsa*** · #6 08-05-2009, 12:29 PM

I removed the secondary cats on my 996 and I was very pleased with the sound. Not too loud cruising and zero drone.

Tomasz · #7 08-06-2009, 12:46 PM

Originally Posted by harryo2b

I've done it. Bought a spare muffler set for cheap, I assume they would be even cheaper now, and cut and gutted it. Removed everything. (used to have the photos on here but that was long ago)

Also there is a Belgian parts dealer that does custom muffler tuning on the cheap as well for 987 cars. PM me for details about them.

Hi:

Did the sound change? If so how? Also, did you remove the old cats only, or anything else?

Tomasz