RX8Club.com - Help!!! my 8 wont idle

I have been having idle issues for a while now, but it usually only happens on a hot day. Now it has gotten so that my car is not driveable. If im driving and i engage the clutch or shift into idle. my car will drop to 750 to idle, then the car will die. any other time i have my foot on the gas. the car runs fine. accelerates alright, no loss in power at any other rpm so i dont think it could be a seal problem. i do have a little vibration at anything below 1500 rpms. my car seems to be running very rich. i thought it might be an ignition problem so i bought the mazsport ignition solution replacing the wires, ignition coils, spark plugs, and i even replaced the maf. my current setup that could possibly reflect these problems are racingbeat intake with cold air duct, underdrive pulley kit, magnaflow catback exhaust, mazsport ignition solution, and a optima yellow top battery. i just installed the ignition solution today. when i started it the first time, it was fine, every time i engaged the clutch or shifted to neutral, it idled perfectly. but after i turned off the car and started it back up again a few minutes later. it wouldnt hold idle again. when i first I do have a small exhaust leak right behind my cat at the gasket. i have bought the gasket but havent fixed it yet. the only thing i can think of to replace next is the rear O2 sensor because ive heard that the sensor also controls the fuel trim for the idle. when i replaced my spark plugs, they were pretty bad but still looked operational but still showed that my car has been running too rich. I know that some people have had fuel trim problems that have changed the intake system, but never heard of anything as bad as it not even holding idle. please any ideas will be greatly appreciated. ive tried almost everything.