Now before anyone says do your research, i can tell you that i have. I have an 06 RX 8 with just over 100k miles. My power steering went out about a year ago. My indicator light came on and obviously the car became very difficult to drive. However for a few months the power steering would temporarily fix itself for a few minutes after i filled the gas tank to full. That eventually went away. I have checked the connectors under the air box multiple times as well as cleaned them and even went as far as to splice them together. Ive check the battery terminals and the fuses. I followed and checked all connections on the harness to make sure there was not a fault somewhere in the wires. I've done the hard reset by leaving the positive connection on the battery disconnected. I recently went on a work trip for 6 months and made sure to leave the battery disconnected. I come home and reconnect everything and give her a start. Obviously after being out of commission for an extension period of time it took a little bit to get her to start but out of this came a new issue. The power steering got worse. Previously i was able to turn the steering wheel with some effort while she was on the ground. However now it feels as if the entire steering column is seized. At this point im not really sure what to do. I took her in for a diagnostics and they pointed to my rack and pinion and steering gear. Has both of them replaced and she drove great for about 1-2 months just for the steering to go out again. I'm at my wits end at this point just trying to figure out what's wrong.

 

Have you done the steering wheel reset? Turn the wheel clockwise until lock, then counterclockwise until lock, and back to the center. If you do this with the key on and the engine off, this should reset the module. If it's still inconsistent, clean the connections at the rack itself with an electronics cleaner. There is one for the torque sensor at the base of the steering column, and another for the motor itself (zip-tied).

If none of these work, I would recommend verifying continuity with a multimeter to ensure that the mini harness at the rack isn't damaged in any way.