Purchased from my buddy a few months ago for dirt cheap(already knowing of certain issues).

2004 Mazda RX8, 6spd manual, 77k miles.

Car does not start when warm, read the forums on here and I replaced-
Spark plugs
wires
coils
crank sensor.
new oil and filter
and seafoamed the proper way
Still no fix, car still won't start when hot but runs better. Less than 200 miles later start getting a rattle sound(marbles in a can) so I did the procedure of removing everything in the way to the ssv, removed the ssv(super nasty) and cleaned spotless. I also cleaned inside of the manifold.
I then cleaned the MAF sensor with rubbing alcohol and let dry. There is still a marble in a can rattle (whatever) drove the car to and from work about 20 miles each way. Drove great besides the rattle, got 10 feet from my driveway and started backfiring a lot and would not idle (does not run).

P0456 code, replaced gas cap and changed nothing.

What. Do. Stumped.

 

Hard warm starts are a symptom of low compression. I"d get it tested before investing any more in fixes. The noise you describe can be coolant flow or detonation. Or a bad bearing. Any chance your intake work left a vacuum leak somewhere or misconnected vacuum lines?

Evap is the only code you have?

 

I think I have an o2 sensor bank 1 sensor 1 since I bought the car. I've known about doing the compression test but there are no dealerships or rotary shops near me, I figured I'd have to rebuild the engine anyways but was hoping to making it last thru winter.

I'm pretty sure I put all hoses back in place. I had my buddy keep it from dying while I sprayed carb cleaner on the vacuum hoses but no spike in the rpms.

 

Can you get the full list of codes and short term/long term fuel trim data from OBD (while your buddy keeps it running). This could be simple. It could also be a dead engine. Pull the spark olugs, see what's on them.

Also was the cat ever checked? You're going to want to make sure it's not clogged before putting a rebuilt engine in there.

 

As of this morning,
p0456
p0033? (o2 sensor heater circuit low bank 1 sensor 1)
I'll have to get the fuel readings tonight after 7pm cst.

I forgot to mention I have a Test pipe in with an o2 sensor instead of the cat atm.

When it first started running really rough, I had my buddy start it and give it enough to idle and not die then unplugged the purge valve located next to the oil filler neck and the car didn't change one bit while it was plugged in or not. Only thing is when it was unplugged it threw the p0443 code. Plug it back in and no more code.

 

My obd tool is to old for fuel trim. Ah well, I guess I'll have to get a newer one soon. I think I'm just gonna put a pin in it for now. I love rotary engines but as of right now, this Renesis sucks A**. Found a guy who wants to do an LS swap on it. Idk, I hate this thing.