Driveability issue

Hi all. I have an 88 mustang that isn't running right. I tried to pull the codes but I guess I;m not doing it right or something...Basically when the car is cold, I can start it and it will fire up and stay running as long as I am giving it throttle or turn the idle screw out far enough that it will stay running (which seems to be quite a bit). If I start it with the maf unplugged it will start with the throttle plate completely closed and idle perfectly.

I should mention I installed new gt40x heads and a trickflow stg 1 cam. I installed the cam dot to dot and the timing is set at 14 deg base.

Symptoms: Poor idle, popping in intake, backfiring on deceleration, and a rapid bucking sensation when trying to cruise at a steady speed around 2-3k rpm.

When I disconnect the Mass air sensor it will start up cold no problem and idle well. No missing or anything, sounds very healthy

Things I have already done:

1.Set TPS voltage and checked for dead spots - OK

2.Mass air conversion with Pro M harness

3.Checked part number on mass air flow sensor - is correct for 5.0
mustang with 19lb inj

4.Tried cleaning sensor - no change

5. Checked vacuum lines - all are hooked up

6. Had a spark plug wire arcing to disptick. Rotor, cap, plugs, and wires are all new. Helped but still not fixed.

7. With key on engine off, I checked terminals A and B on the MAF sensor connector, unplugged from the sensor. From what I understand I must have more than 10.5 volts. I had 12v

8. I then checked the resistance between C & D and B&D. I found above 10,000 ohms on both of those circuits which I think is normal.

9. When I had the engine running, I had power and ground on A & B, but when I tried to get a voltage reading between C & D, I could not get one, which makes me think there is an open circuit inside the mass air sensor because as I said before, my resistance was over 10,000 ohms with the which is what ford's specifies in their test procedure.

I'm not sure if it means anything but when I had the key on, engine off I checked voltage between C & B and had 5.69v.

If anyone has any advice it would be appreciated.