Any work done on it lately? I only ask because of the IAC connector is not unique and can be plugged in to the wrong thing.

So you MAF is guessing what the engine needs for fuel and O2 sensor is reporting how well it guessed. If the two are seriously out of range to each other, you get both codes. This almost always happens when you have a significant source of air post MAF.

Look for cracks in the intake tube, IAC pipes and brake booster line, check valve, or even the booster itself.

The running on three cylinders feel is likely a very lean condition causing one or more cylinders to misfire.

that being said, you still have a serious bad O2 sensor a a possibility but that would almost have to be the heater circuit bleeding voltage to the sensors side.