2007 Chevy Equinox spark knocking and slight stalling upon

I had a part replaced earlier this year ( I think it was like a spark plug socket) because some gas I put it was faulty and blew out the spark plug socket. The car did not pick up on exceleration, and had some knocking. Once the part was replaced it worked fine. It's doing the same thing again. Could it be the gas, the fuel injector or something else otr the same problem/.