Land Rover Repair: 2000 Disco, o2 sensors, sensor signals

Question
I have a 2000 disco and just got it checked for the fault codes which were:
P1590 (Idle air control and speed sensor)
P1174 (Air and Fuel metering)
P1300 (Ignition system)
P0562 (System Voltage Low)
O2 sensors (Front)

I was wondering what needs to be changed to fix these things, obviously the front O2 sensor, but is there anything else?

I changed the alternator before I got it checked but it still has a system voltage low code, I don't understand.

I really appreciate any help you can offer.  Thank you.

Shawn

Answer
The codes you have to not point to any parts that should be changed, not even o2 sensors.  The codes tell you there are misture problems, a misfire, problems with the o2 sensor signals . . . all of which need to be tested.

The next step would be to observe the actual sensor data when the motor is running and figure out what's wrong.

People often have the misconception that fault codes simply direct you to replace parts.  They don't.  They give clues to tests you should run.

In your case the next step would depend upon what the live data showed.