Hello,
With respect, the vehicle is 13 years old. At some point, your vehicle become yours, and not an object of manufacturer responsibility.
Hard to say why some cars had a similar part covered, and I'm sorry that's the case for you.
Nonetheless, it sounds like testing needs performed on your vehicle to find out what's happening in various areas.
How did you test your mass air flow sensor? How did you test the air temperature sensor concern?
Keep in mind that a P0171 is a lean code for engine performance. This can be caused by a vacuum leak, an air intake leak, a mass air flow sensor concern, a wiring concern, or (rarely) an oxygen sensor concern. Testing must be performed to hone in on the root cause.
The chirping concern sounds like something rotational making noise; check the accessory drive area where the belt is to see if you can narrow down the source there. Might need to remove the belt and run the engine to see if the noise stays or goes.
There is no adjustment for your compressor clutch, and for that system testing would be needed to see where that problem is originating from. A visual inspection of clutch gap isn't enough to go on or condemn anything.
Good luck!
