Boxster catalytic converters - fix, replacement?

[Starter986]

I think one, as a Cali resident, miight hit AZ or NV and purchase from private sellers parting out thheir 986. Likewise Cali.

I mean... if I were parting out my car I'm not reporting to anyone I sold the cats to an enthusiast.

[Homeoboxter]

Someone is selling a pair of cats for the Boxster for $500 which I think is a great price. Allegedly the car they were taken from had only 70k miles. I'll check them out tomorrow. Is there a way to get an idea about if they are indeed good condition? I can check the rattle, I can look into the honeycomb with a borescope for soot, anything else? Thanks for any tips!

[Homeoboxter]

OK, so I got lucky with removing the header bolts, I used some Kroil and they all came out easily. One was already broken into the head but I could remove it by hand...

I found a used cat in L.A., here's the old and the replacement:



I installed it and now there is no rattle, yayyy!

I also looked at the efficiency of the new cat.
Looks pretty good to me.



Here's bank 2, for reference, also good:



In the rattling one the post-cat signal sometimes was clearly following the pre-cat's signal. Didn't throw a code though.

I uploaded a video of both here, just fyi:
https://www.youtube.com/shorts/wrMxLf7S0Rc
https://www.youtube.com/shorts/co477gS3rZE

[Homeoboxter]

Just wanted to share a few pics at the end of this thread. I shipped out the old catalytic converter to a recycling company and I cut it apart to reduce shipping cost which allowed me to take a look at the catalytic element. The honeycomb is seriously damaged, but surprisingly on the output side, and hence the rattle. I'm not sure what can cause this - some detonation? Or just aging? Interestingly, it was still doing its job, has never thrown a code, although the post-cat O2 sensor signal was not as flat as the same on the other bank..