Copied from a different forum (modifiedmazdas.com)

Fuel Filter: (60-100,000 miles)
Symptoms of a plugged sock are a steady loss of power during or after a long
steady hill climb or high speed run. The sock pores slowly get plugged by loose
pieces of dirt, and the problem disappears for a while after simply stopping for
lunch or fuel. Note - This condition will NOT post a Check Engine light, or store
a trouble code for the Mazda dealer's computer to read, so if you experience it, you are pretty much on your own, unless you can convince the mechanic to take some basic troubleshooting steps....

You will need a specialized tool to get the fuel pump out of the fuel tank. The tool is available at;
Amazon $18.95
Napa: (Lock Technologies LTI 940/ NAPA 770-8001) $23.00

Might be your fuel filter, the part where you stated the issue went away made me search a little more. Typically when your cat is clogged, the issue will not go away. However I still believe you need to get your cat checked.

Does the above resemble any symptoms your experiencing?

 

Since it sounds like your CAT took the long road out the back of your exhaust and the pressure test your buddy did came up normal, it sounds to me like you now have a gutted CAT (which you should still get replaced). I am surprised you never threw a CEL. So the clog in your CAT should be gone. The loss of power now is due to your f'd up spark plugs, coils, and wires. Get them replaced ASAP.

 

It will only take a few drive cycles for him to get a CEL. The misfires alone should cause this let alone the cat failure code.

Whether its the cat or not, with the bottom of that thing blown out, I would still try to get it replaced under warranty.

My thesis:

1) Highly likely - Needs new CAT

2) Possible - Fuel Filter

3) Not Likely - Engine Failure

4) The definate - Replace your damn coils/plugs/wires before anything else breaks!

 

Which is why I am stunned he has not gotten a CEL, or at least not that he has told us of.

I couldn't have said it better myself

 

Yeah, because sometimes when I go over bumps, I hear almost the same noise. Well, I drove it up and down the block real quick to see if the problems only happened when the car was warmed up, or cooler.

It stalled right on the corner as I was doing a U-Turn, and stopped right infront of my house, and turned back on, then stalled right away.

IF I can jack it up on the street without much danger, IE getting crushed, I am going to take it apart tomorrow before work, and take a look for myself.

 

I did have a Check engine light, maybe 4 weeks or so ago coming back from about a hour trip, it was a P296 and read: Post catalyst fuel trim too lean bank 1.
I called the dealership about it, and they said it was just a bad rear o2 sensor.

Aside from that one check engine light, the only other one I had was a misfire, which I am pretty positive came from me not letting the car warm up enough during the winter.

 

WOW. Too bad you didnt have that call on recording, this whole repair would be free guaranteed.

And these are the 'experts' working on our car

The misfire came from you having ignition components that are 20K miles past their suggested interval. These misfires caused the second code stating you were running too lean. Running too lean makes your cat run hotter. Your cat running too hot means it will melt and fail. Failing cat causes all your symptoms. These symptoms cause you to post on RX8 club. You posting on rx8club yields the answers I just gave you.

This is what happened, Id bet my RX8 on it ^

 

Well.............now that we have this solved, we can all just move along.

Was reading over the last couple of days, but not posting.

 

Well that would be awesome if the whole repair was free! Though, I do feel like your kidding about that <3

All I can do is wait until this upcoming Tuesday and find out.

 

Well, my car has been at the dealership for two days. They have no clue what is wrong.

They took it for a drive today, and no problems, they checked my cat, motor mounts, intake, all looking/preforming good. They had mentioned that a Mazda Tech said something about a TSB for a lose of power, so there gonna try that and see what happens.

 

So I got a new cat. That wasn't the problem. Dealership just called me, and wants all receipts of oil changes, so they can fax them to Mazda. I do all my own oil changes. I'm assuming I need a new engine, and I'm 100% completely lost on what to do.

 

if you cant find a reciept pull your bank statements that show where autozone or so and so charged your card...

 

^^ Not a bad idea.

Im so paranoid about my engine needing replacement, I do not have all my RO's or receipts personally. So I would also be in the same boat.

*Crossing fingers**

 

I always pay everything in cash, so that wouldn't work.

Although, the good news is, I do need a new engine. It has oil blow by. It is covered 100% from Mazda, so I get one for freeee!!!!! I'm so excited!!!

 

Nice, they didnt require service records?

 

Nope, no records. They called me and triple checked. All good, can't wait!

 

Just a little update:

I took it in to the dealership last Tuesday to get my engine replaced, JUST got it back yesterday (Tuesday). Car is running sweet! Kinda sad though because I have been doing a lot of reading on breaking in, and not going to higher RPM's until after 1000 miles or so.

The car is running great, and I just wanted to thank you all for helping me from the beginning!

 

Good to hear! Glad Mazda made you happy!

 

Op there's nothing unique about your issue. Do a little research. Your cat has failed and has become clogged. Perfect opportunity to get yourself a midpipe or highflow cat.

 

His engine was bad, he now has a new one.

Way to read

just kidding