My wife's RX-8 is acting up in the power steering category. Light comes on and off. When it''s off the cars runs smooth, but when the light comes on the car is hard to turn. I already replaced the rack and pinion, but still nothing. What else should I do to get tthis car to drive smoothly again?

Question edited for full 'year make model' in that order.
Question moved to correct category.

Service manual in the link, but for your electrical problem, you will need a mobile auto electrician with a pro grade scan tool computer to diagnose the issue.

https://www.google.com/search?q=2004+mazda+rx8+service+manual+pdf

..

If the only indication you have is the check engine light and the engine is still strong and smooth, go ahead and drive. If the power is noticeably down and the engine is shaking, better not to.

The codes that indicate specific cylinder misfires are P03xx, where the xx represents the cylinder that it says is misfiring - there will be one code for each accused cylinder. However, misfire codes are some of the most common false codes. All the computer knows is that the crankshaft is averaging slightly lower speed after the cylinder was supposed to fire - if it is slower the cylinder must not be firing regularly, right? Not necessarily.

The first thing you will want to do is to reset the codes if you didn't when you read them. If they come back right away there may be something to them, but if they come back in after a while the computer's teasing you. If the light doesn't come back on right away, try fuel injector cleaner in the tank. If it has been a while since the last tune-up, now is the time. After these steps, reset the codes and see how it does. Because you didn't mention poor performance or rough running I think that will do it.

Change the Steering Rack

One of two things have happened:

1. Your power steering pump went out and needs to be replaced or,
2. The drive belt that controls the PS pump broke

The RX8 has only two drive belts so if they are both fine and none are broken then it meant that the PS pump itself has went out and needs to be replaced.

Let me know what you think and dont forget to rate the solution.

Thank you and have a great day!

could be the steering colum bushes, does it make agrating sound inside the car? or power steering problem, check power steering resovour levels , if this is full it could be a leakage in pipes or faulty pump

Ignore earlier post - the RX-8 has an electric power assisted steering system - there are no hydraulics, and therefore no PAS fluid.

You either lost your belt, or the oil is gone from a broken hose.

sounds like it needs to be taken to a madza approved repairer for then to be plugged in for a dianostic annalisis, too many warning lights for one fuse.

I would check your power steering fluid level first. If it's full your power steering pump is bad.

The Mazda RX8 has electric power steering there is no fluid. You may have a problem with you electronic power steering control moduel, or the power steering pump