It's a single pipe from the engine to the muffler, so what you feel at the tips has nothing to do with anything except the muffler.

Welp.

https://cimg4.ibsrv.net/gimg/www.rx8...b52c25b7b5.jpg

https://cimg5.ibsrv.net/gimg/www.rx8...1fdb7dc67e.jpg

Finding this took Jim at JPR basically no time. It's utterly beyond me how the dealership didn't find this in two visits and probably 3 total hours in the shop. Either way, BIG thanks to Jim for the diagnosis, and to gwilliams6 for facilitating!

Now to get warranty service!

You're welcome.

lol yep, you called it!

So apparently there are no Series 2 cats in the US, at all. The dealership where I'm having the service done (NOT the original dealership) said mine had to be "overnighted" from Canada, which will actually take at least 3 days. So basically, it'll have been a month from when the problem came up until when it was fixed. And over 1500 miles driven with a clogged cat. All for an issue that should have taken an hour to diagnose and less than an hour to fix. Bloody hell.

I'm so frustrated by how much inconvenience the first dealership's incompetence has caused me. I know others have gone through much worse, and I can't even imagine how pissed they must be. Almost makes me look forward to when the warranty expires and I do more of my own work again. :-P

Your new cat is very expensive, be sure to stay on top of your ignition health.
If I were you, I'd take it off ASAP and get a midpipe so that if you ever need it a good cat, you'll have it.
If you sell the 8, you could get some serious money for the cat.

He should be getting this one for free unless he's over 80k miles: https://nepis.epa.gov/Exe/ZyPDF.cgi?Dockey=P100NNQH.pdf

I would take it off even if the car is still under warranty.

Good call.

I had figured I'd go with the Service 2 schedule's 35k intervals for spark plugs, and maybe do coils and wires at the same time for good measure. Haven't had any (identifiable) ignition issues so far, so I figured I was on the right track. Now I think I'll stick to 30k or less and DEFINITELY do coils and wires each time, just out of caution.

Makes sense. The main thing stopping me is the potential for higher emissions levels. Don't want to get into the details, but it's not something I'm comfortable with right now. Happy to hear any feedback on that point.

I have a BHR for several reasons, 1st, peace of mind, 2nd, sound, and then slight increase in performance & MPG.
If you want to keep it on for ethical or environmental reasons, that's cool too, and totally understandable.

Yes, it's recommended that coils, wires, & plugs be changed every 30k.
If Mazda would have recognized that early on, they might have had fewer problems with failures.

Yes fortunately his new cat is covered under his Mazda warranty. In Pa. were IamFodi lives, a catless RX8 won't pass emissions. So thankfully if his cat had to quit, it quit before he was over 80k miles. I was happy to assist a fellow RX8 club member.

There are just people in my life whom I'd rather not expose to excess emissions. If it weren't for that, I'd be all over it. More power, more MPG, one less failure point... Seems like a slam-dunk!

Just for clarification the catalytic converter falls under a federal warranty that manufactures of vehicles model year 1995 and later have to honor.

The link in my first post goes over it in some depth.

Cat has been replaced. Power is back! So, so nice to have an RX-8 power band again!

FWIW: Piazza Mazda in West Chester, PA treated me really well. Fast, effective, on-point, no-nonsense. The experience was night-and-day compared with the slowness and incompetence at the previous dealership.

Great result IamFodi !!