Engine trouble
 

trouble with 04 RX8 ST had the motor replaced twice, replace plugs and wires recently, ran seafoam through the car disconnected the CAT from the car. flushed the coolent system. Still having issues the car is about a ten mile car It runs perfect until the car warms up. Once it is warm the coolent light will come on and a few miles later the car will start to cut out. If you need to stop in traffic the car will die or get sluggish and lose power. Cut the car off and let set it will run good again for awhile Just wondering what to try next if anyone could help.

Checked your thermostat?
When you say you "disconnected the CAT from the car", what did you replace it with?
Any CEL codes?

Just disconected the CAT and drove it still had the same result just was a little louder well alot louder

a lot louder...probably a lot warmer as you shot flames all over the bottom of your car and probably started melting some things. Im sure your drive shaft wasn't too happy about that idea either. Now you should have a bunch of codes to read.

You should never run open headers unless you have a way to send the exhaust out the side of the car. Did you put up a heat shield? Did you melt the wiring harness for the o2 sensors?