So I’ve got a 2004 manual RX8 and I’ve got a couple problems going on right now. 1) My power steering goes out just about everyday, I’ve cleaned the connectors and everything but it refuses to work properly. If the PS is working, turning the steering wheel to the left is a bit weird. It feels like it’s getting caught on something and then slips off of it. 2) Oftentimes on the highway, when I’m in 4-6th gear, there is a loud rattling noise that seems to come from almost behind the gas pedal. If I keep pushing and go into lower gears, the car loses acceleration power and the rattling comes about in those gears as well.

 

I would recommend replacing the harness that is a known problem.
Its a safety thing right.
Loud rattle behind the gas pedal needs more of a description.
Throwing any codes?
How long have u had this car?

 

I put in a video I took of it, this was after getting off the highway, I was in third gear and it just has no acceleration. I listened a bit more carefully and it actually sounds more like it’s coming from the transmission tunnel.

 

Sounds like a bad catal converter.
If it broke up and clogged that xould cause your rattling and performance issues.
Seems like you'd be getting a flashing CEL for misfires though.
Go to a parts store and get a free OBD scan.
Get the cat inspected ASAP.
Misfires kill cats, bad cats kill engines.