engine stall

What is your question?

Around March 2015, the engine warning lights went on (VSC and engine check). took it to Mechanic, ran diagnostics, and then replaced the 02 sensor and the MAF. At first no problems. Few weeks later stared experiencing stalls and weakness when driving. Took it back, they couldn't get it to stall, cleaned some things up, recommended using high test, didn't charge me and it was running great. Recently it started again, It has happened 2x while I was making a turn, 2 times while stopping at a stop sign, one time, while waiting for a light. Leading up to these episodes, I have felt a "weakness" when driving. Took it to the mechanic again yesterday, got the fuel system cleaned, plugs changed and am crossing my fingers it doesn't happen again. Any ideas??? I'm desperate and scared to drive it now. Thanks.