So my car is a 2006 Rx-8 Manual. The engine has about 3k miles on it and it's a street port with race internals. I recently installed the racing beat intake kit and it drove like a dream! Until one day it didn't. All of the sudden the car started to rev on its own up to about 4k rpm and it seemed like it was fuel cutting and it would stall. Then it wouldn't start on its own but when I put the accelerator to the floor for deflood mode it would start, which is odd because that's suppose to prevent fuel flow. The temp gauge would drop to zero, the traction control light would come on, amongst other things. I replaced the battery and the terminals, I have checked and fixed the grounds that I moved when I installed the intake. And now these are the only two codes that come on. But the car still stalls out but only when it's heat soaked. It'll start right up when cold and be perfectly fine until at operating temp. Then the fans kick on and the temp gauge will bottom out. The the car will idle hunt. Then the fans kick on high, the temp gauge slowly comes back up, and the car stall, all at the same time. I wait 5 minutes and the car will fire right back up. I'm at a loss with this

​​​​​​I would like to add that the whole time my power steering hasn't worked either, but it's never caused a problem. The power steering stopped working when I had the radiator replaced which seems odd. Checked the fuses they're good. Seems the power connectors for the power steering are running low voltage. 5-8 volts respectively. The codes for the power steering are as follows, C1099, B1342, B2278, and U1900. This may need a separate thread but I put it in just in case they may be connected.

 

Sounds like you have electrical gremnlins. The circuit high and circuit low codes mean either short or broken circuits. Possible the wiring harness was pinched when the engine was reinstalled? What is the system voltage at idle and when you're driving?

 

Well I haven't had any issues since the engine was reinstalled. This started happened days after I installed the intake. So I'm thinking it's related to that. I have to grounds underneath the air box that I had to move to make room but they are both cleaned and secured. After putting the new battery and terminals in, the problem seemed to get better. Could it be alternator related? I never get the battery light on my dash though. I will get the system voltage tested and send an update