Need some help trouble shooting

I have an 87 GT with a few mods. Converted to Mass Air. I'ts started running like crap, it will idle for a few minutes then it will start surging and finally shut off. It loses power in the mid and upper rpm range and it runs rich while I'm trying to test it. I have two new O2 sensors a new TFI module and a new Idle Air Control Sensor. It maintains 35psi fuel pressure the air/fuel gauge stays on the rich side now all the time. Also has new distrubitor cap and rotor button. It has a C&L 73mm mass air.

Checked the codes and It keeps coming up KOEO 21 81 82 95 15 and Engine on 98 and 66

21 is ECT
81 and 82 are the smog system
95 Fuel pump: open, bad ground or always on - Power / Fuel Pump Circuits
15 No Keep Alive Memory power to PCM pin 1 or bad PCM (Memory Test Failure)

98 Did not pass KOEO yet (Get 11 in KOEO first)
66 Vane Air Flow (VAF) or Mass Air Flow (MAF) signal low - VAF MAF

Any suggestions on where to go from here, I'm an old school drag racer and used to dealing with carb engines. I need a little help with the electronics on this car. LOL

I would think since the MAF is larger than stock and set up for 24lb injectors that it might give a code.

I pulled the connector from the MAF and it still runs like crap, so I kind of ruled out the MAF giving me any problems. (But I'm an amateur with Fuel Injection) and I don't know if it would make a difference.

I do have a chip but I pulled it before all the testing. Timing is 12 degrees base at idle, I cant figure out what is making it surge and die when idling and why it loses power in the mid to upper RPM range.

Could my ECM be fried since I'm getting code 15?

Sorry about that, I should have listed all the mods. I'm frustrated with this thing because I'm having to fix all the Jerry Rigging from the previous owner.

I thought about the code 15 and I might be getting that from disconnecting the battery and clearing the codes when I change a different part.

Timing was set with "spout connector" removed.