04 rx8 drives great - turns on great - but sometimes wont start after driving

hey guys, this is my second post on this forum and want to say so far all you guys are the best!

here is my situation im in...

let me start off by giving you some info on my 8.

its an 04 6speed with almost 119K miles.

I had my plugs, coils, and wires replaced. Had a new high powered starter installed, replaced my fuel pump, replaced the throttle body with a used one and of course an oil change with 5-20.



so onto my issue...



the car starts up great when the engine is cold. it drives great, barely any hesitation in idle, but SOMETIMES it will stall when I have it in gear at a light and not revving the gas.



when I turn my 8 off, sometimes right away it turns on when i crank it but sometimes it doesnt. it takes me 4-6 times of cranking for it to turn on. I dont think theres a vacuum leak, and if there is, I sure as hell cant find it.

the compression is good. everything is good.



sometimes i get my check engine light saying my cat is below threshold, but i erase the code every time. it comes back on every 50 miles or so...



any ideas? thanks in advance guys

:confused: