After replacing the Engine Coolant Temperature sensor(per the OBD code reader), the car runs much better, but it now stutters when accelerating. It seems to run pretty good at lower RPMs.

The following have been done:

Throttle-body and IAC valve cleaned. It seems to idle better.
Fuel pressure regulator swapped with a working one. No change.
Ignition power stage unit swapped with a working one. No change.

Many vacuum hoses replaced. Spraying the area with carb cleaner at idle doesn't make a difference. It idles well.

New cap and rotor. Plugs have less than 1000 miles on them. Tested the wires using an inductive tester and everything seems to be okay.

Gas tank 1/2 full. Both fuel pumps can be heard.

It seems to be "bogging" according to the FAQ description. While there was no AMM code, there is now. After replacing the AMM with a known working one, there was no change in performance. On a short test drive, I unplugged the AMM to hopefully experience the car running better, but it stalled. Plugged it back in, and putted as with the original AMM.

Now the AMM code is being shown, and am going to reset it. I would like to look for any vacuum leaks that may occur when accelerating, but am not sure how to do this. Also going to swap the fuel pump relay.

Do I need to check the pumping rate of the main fuel pump even though the regulator is "good"? Any tips on testing the connections of the harness at the AMM?

Thanks for any suggestions.