This car does not have MAF sensor, it uses MAP instead. Need to remove that and clean air passage to it using carb cleaner. IAC valve tends to be a problem on these cars but it will cause erratic idle. At that age I would remove and clean throttle body whole intake manifold - will be great improvement. Takes few hours first time.

Could be vacuum leak. Pretty bad, should be easy to spot.

It is the highest point in the middle of the motor. You can't miss it.

What is the error code?

I had to replace ignition switch with the same symptoms at 175K. It was replaced by recall at ~50K before. All job was 1 hour including beer. Try wiggle your key in ignition while running. If you can turn it off without distinct feeling of 'click' in the ignition you need to replace the switch. It was switching off for me when I took my leg from the gas pedal on intersections and touched keys hanging from car hey.