Removed 2nd cats from 987.2 headers

As we all know, the 987.2 is much quieter than the 987.1 , and there has been some speculation that this could be due to having 2 sets of cats in the OEM exhaust manifolds. Even though the 987.2 mufflers don't have any cats like the 987.1 mufflers do, the 987.2 is still much, much quieter than either of my 987.1s. So I picked up a set of used OEM Spyder headers (which are the same as all 987.2 headers ) from a forum member with the intent of replacing the cats with 200- or 400-cell cats. The hope was to get a more aggressive sound, or really, any sound at all But then I found this thread: 987-2 Exhaust system explained - 987-2 Series (Boxster, Boxster S, Spyder) - RennTech.org Community As Gert shows, the 2 cats in each 987.2 manifold are both 400-cell cats already and are separated by about 3/4" of free space. Furthermore, the 2nd O2 sensor is between the 1st and 2nd cats, which implies that the ECU cannot detect when the 2nd cat is missing.... So instead of hacking up the manifolds and buying new cats, I just removed the rear cats from both manifolds using a drill, a paddle bit, a big screwdriver, and a shopvac. Using a flashlight to look into the bung for the 2nd O2 sensor, I was able to make sure I did not damage the front cats during the procedure. The whole job takes about 1 hour (including removal/install), and the change is undetectable to a visual inspection or through the OBD port. I still have the stock exhaust. The car is now definitely louder than a stock 987.1. I detect a little less vacuum cleaner sound and a little more cup car sound, but it is nowhere near aggressive. I'd liken the change to desnorkeling. It now sounds more like you'd expect a conservative sports car to sound from the factory (seriously, my family CX5 is louder than a bone-stock 987.2). Since I'm more of a Borla-type guy, it's still not loud enough for me. Fortunately, I have a spare set of mufflers just sitting in my garage, so I'll be hacking them up in the next few weeks.

What about removing the primary cat?

Yeah, I'll probably fully de-cat the old pair of manifolds and try that out in a few months.

It makes me happy to see a valuable thread worth to read and comment on for once. Nowadays it is mostly bickering and sponsor-advertising in here. Not many facts, just opinions. This thread involves facts; very refreshing! Even though the info is, or should be, "old" and known; I think your approach is worth noting. An inexpensive way to get a better sound and some more power. And IMO is a better way than completely gutting headers or buying expensive (read;overpriced) so called race headers. This mod should pick up 10hp-ish, make for a more aggressive sound and still pass emissions. In fact this is what Gert himself does and offers via his website. His sport headers are just that; OEM-ones that have the rear converters removed as well as the front replaced with a pair of HJS converters. I have them myself and love them!

I have a spyder without pse and would like a bit more engine sound. It would be great to hear the exhaust with this mod. Anyway to post a short video? Sent from my SM-N910T using Tapatalk

This is good idea. Besides the cats that are chocking the gas flow - the manifold runners design is really bad (dimensions and form), so this is also robs a lot of power and sound.

Ah! I didn't make the connection that Carnewal == Gert. I guess he's doing 200-cell installs, and his welds look good enough to possibly pass a visual. Here, however, we don't have visual inspections. I've driven the car a bit more now, and the sound is better than I initially thought. It's a nice sound at idle and rips up to 7k rpm with a nice, smooth mellow sound. I need to fix a few more unrelated things and will then post some video. Hopefully by next weekend.

+1 for the Carnewal = Gert modified headers .

Looking forward to seeing the video. Sent from my SM-N910T using Tapatalk

Did the video of the 987.2 headers with gutted secondary cats ever happen?

No, the car developed some issue with the cam timing gear slipping or some BS (speculation by dealer). The dealer seemed less than capable of fixing it, so I ditched the car for a big loss. My last 2 987.2s ended my lucky streak with buying used Porsches, so I'm taking a break for a few years... I still have a set of 987.2 headers sitting around (with all cats intact) if anyone wants to play with them.

I may be interested in the headers . I have an =09 2.9 base. Are your headers compatible? TIA

I think all 987.2 headers are the same (base, S, Spyder and Cayman R). But the headers are gone guys, thanks for the interest. Maybe Alanine can eventually make that video that I never got around to...