Any time I hear "cranks but only runs if I keep my foot on the gas", it turns out to be a gummed up Idle Air Control (IAC).
Not saying it might not be something else but that is where I would look first particularly if no codes are present (mechanical problems rarely set codes).
Throttle plate is designed to close fully and all idle air is through the IAC. If gummed up you do not get any and it stalls when you take your foot off the gas.
I do not believe in removing the MAF screen, is designed to shape the air flow through the MAF. Have not seen any indication that it helps airflow, that is not the choke point.
160 baud scan tool is no good on 8192 baud P4 computer system as used by "C" engine.
Are a number of OTC 2000s on eBay right now under $50, just make sure you get a GM cartridge (or 3 in 1 or "Pathfinder" with GM) cartridge through your year (last was 1993) and a GM 12 pin connector adapter.
I consider two tools essential for these cars: a good scan tool and a fuel pressure guage.