what can be done to ecm,for how much, who to send it to,for stock engine is it worth it?

 

for 100$, Phearable can do it, and then they will ship it back set up the way you want,
i suggest doing a few upgrades first, maybe get a cam, and a few other bolt ons then get it chipped and tuned. also you will need a obd2a to obd1 conversion harness and a obd1 ecu, get the obd1 ecu sent off to get chipped and just drive with your stock ecu til your ready.