Ive had my 05 Automatic RX8 for about three months now. 71000 miles

When i first got the car it couldn't hold an idle after driving it for about 10 minutes. I diagnosed and fixed some problems and it seemed to work fine. Though yesterday i was driving it around a lot and doing lots of small stops so i had to turn the car on and off again. i noticed the idle was getting lower and lower every time. Finally after a while it got down to about 500 RPM and it died. i turned it back on and turned the AC off which helped bring the idle back to around 700 RPM.

The plugs, coils, plug wires, and MAF were replaced around 500 miles ago.
Everything else seems to be original.

Can someone tell me what i can do to fix this?

 

Check your battery. Make sure there's no corrosion and all wires are tight and secure. Check all grounding points, also.

 

Where would all of the grounding points be?

 

Keeping the Engine at an Idle
• Ignition Coils
• Spark Plugs
• Spark Plug Wires
• Engine Compression
• E-Shaft Sensor (ESS)
• Mass Air Flow Sensor (MAF)
• Front O2 sensor
• Catalytic Converter (Cat)
• Intake Vaccum