2000 Mitsubishi Galant Engine oil used?

Hello

I just changed the oil in my Galant, but I realized I put in 5W-20 instead of 5W-30! Could this be the cause of my engine stalling, or (like I asked in my other question that was answered) does my disconnecting of my battery cause this problem as the ECM relearns all the data it lost? Mitsubishi recommends 5W or 10W-30 oil in this vehicle, but I bought the oil because I thought it would be the same for my Mitsubishi as in my Honda but it didnt end up that way. Let me know!