Garrett,
I did not see anywhere in your posts where you pulled the #6 fuse to clear the 1-2-1 code when you swapped MAF's. Even though your symptoms remain, it may be good practice to start fresh with the codes when you replace something.

I hope you solve it this weekend, as i know how frustrated you must feel.
Regards
Miguel
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Happy Motoring! 92' and 93' 240's past cars "74 140, '75 140, '86 240, '87 240 wagon, '02 S60.

I kinda sounds like the timing has jumped. Have you checked the timing belt?

I cleaned the throttle body for preventative maintenance and it was filthy, however it did not help my situation. I did replace the ICV with a used part to see if that changed anything, unfortunately it did not. I replaced it back with the original and no change. I tried the hose pinch technique on both of them and the idle did not change. Could that mean that the ICV is faulty on the electrical side. I did check to see if they cylinder inside moved freely with my finger and it did on booth of them. Could it still be bad?

That 1-2-1 appears to be the MAFS.

Try unplugging your MAFS or AMM if you prefer, do you know where to find it?

Everytime I have had a rough idle condition the very first thing I do is clean the throttle body.

For some reason these cars need to have the throttle body cleaned more often than any car I've ever owned (or heard of).

The other consideration is the Idle Air Controller. There is a ~1.5" diameter hose that comes off of your air intake hose (the black accordian looking thing attached to the throttle body). Follow that small black hose down and you will find it attached to an aluminum cylinder shaped part that will have another small black hose coming out at 90 degrees to the aluminum cylinder and wires attached to the back of the aluminum cylinder.

The IAC allows air to bypass the throttle plate while the throttle plate is closed.

One way to test it is to clamp down the small black hose so it cuts off the air supply to the main air duct. If there is no change in running condition then the IAC is not functioning. If the engine idles lower and/or dies then your IAC is at least providing *some* amount of air.

You can also remove the IAC and see if you can manually move the valve inside it, it is a barrel that rotates inside the aluminum cylinder. You can see this barrel when looking into the IAC through the port that is perpendicular to the aluminum body of the IAC. Try pushing it in both directions, as long as it moves one of the two directions it is not frozen. If you can't move it at all, it's locked up. Use your finger or another soft object, you do not want to damage the valve.

Another possibility is a vacuum leak, most likely a disconnected line leading back to the throttle body or air intake duct. I don't have my book with me to look up that code but I think it's online somewhere.

Does the car run fine otherwise? Did it just start doing this suddenly or did it slowly degrade?