Sudden and unexpected death
 

So about my 04 rx8.
Has about 18-20k miles on a new engine and I put partial synthetic oil in it every 3-4 weeks. Recently it's been seeming as though it struggles slightly on ignition but then runs just fine. Other than that no symptoms. Tonight however after pulling into the road it immediately lost power on revs and the only way I can describe the sensation of the engine is that it felt rough and was making a deeper tone than usual. CEL came on blinking and weirdly got better BREIFLY, for about two minutes then instantly spiraled. It couldn't maintain power on idle and died twice after that. Oh and also, saw bits of red hot something or other come out the exhaust while on the road. That part seems somewhat significant. My suspicion is that its my apex seals? Thoughts anyone?

Do you still have a cat?
Could be chunks of the strata blowing out of your exhaust and blocking it.

Blinking CEL means misfires, which dumps fuel into the cat, making the strata glow.
Failure is usually clogging, melting or breaking up, which can cause the symptoms you are experiencing.
If you have one, drop it and inspect it.
In it is broken up you could have chunks in the muffler also.

Yeah it still has the cat. So to clarify you think dropping the cat and either gutting it or opening it up as a single pipe will be a quick solution? What's the worst case scenario?

I really doubt it's your cat or an engine failure. I had the exact same thing happen to me, and it was a rather interesting failure. Assuming your cat is in passable condition, it probably wasn't the cause.

One of my coils had experienced what I like to call a total existence failure. The first thing I would check are your coils. Cat failures usually aren't so sudden.

Here's mine:
https://www.rx8club.com/rx-8-discuss...3/#post4619819

Yes, drop it and inspect it.
If it was the glowing pieces of cat you saw behind you it should be pretty obvious, your cat will either be hollow or have a big hole through it.
You would want to knock out any remaining pieces in the cat with a pry bar or something.
Try to take your oxygen sensor out first so you don't damage it.
Then be sure you have no pieces lodged in your exhaust pipe or muffler, try to shake it out.
Then you need to figure out your misfire problem.
Usually coils, plugs, & wires will be the culprit.
Worst case, it's been clogged for a while & damaged your engine, but one thing at a time.
Good luck!

Ok that makes sense, a combination of the two. Thanks a bunch guys, should I post again when I find out what's wrong to let you know what the problem was? Not sure if that would help anyone else or not

Go for it!

Yes, it's good to know when things get resolved for the people who offer help, and for others searching for it.