I pulled a STUPID - MAF Question

[Sentientbydesign]

TL;DR:
Car: 99 G20t
Problem: Tested MAF WRONG. With the engine running, I probed what I believe was the harness ground and the 5V signal wires thinking this would give me a sensor voltage (I got 1.6V BTW).

Symptom: MAF isn't working properly now. Idle is rough. Serious lack of power.

Just picked up a 99 G20t with 5 speed. Fun little car, but needs a LOT of work. I've been having a hesitation/bucking issue. It's not very noticeable, but it annoyed me.
1) VC was leaking, so I replaced the gasket. Still had the problem.
2) Cleaned the MAF sensor. Still had the problem.
3) Replaced the plugs with NGK iridium. Still had the problem.
4) Checked for cracked hoses. Replaced 3 of them. Still had the problem.
5) Checked the distributor. Noticed one wire was kind of fried and disconnected. Cleaned the terminal and reconnected (waiting on funds before buying new wires and distributor cap). Still had the problem.
6) So today, I started playing with the MAF after reading that it might be the issue. I first pulled the harness while the engine was idling. Engine stopped. Turned it on again with MAF disconnected and it idled. A little rough and high, but idled. Then I plugged it back in with the engine still idling and it adjusted (poorly).

Then I decided to test each wire against ground and got 14v, and <1v on the other two wires. Then I decided to probe (what I believe was) the harness ground and signal wire. I got 1.6v. Engine was still idling rough. I turned the car off. Reset the CEL codes and restarted the engine. Now the idle is really rough and lacks power.

Question: SOOO...Was it wrong to test those two wires or was it wrong to plug the MAF harness in with the engine running? Any speculation as to whether I fried the sensor or my ECU? I'm not getting a CEL.