Driving to work today, tried to pass someone, i hit the gas a little harder than i would normally, I heard a loud POP and the car just died. Dash and electrical still on. I coasted to the side of the road and was towed home. The car is turning over, but it would not restart. Only mod i really have is no mufflers.

For the past few days, I've had Service Engine light on and code PO151 - Oxygen O2 Sensor Circuit Low Voltage (Bank 2, Sensor 1). I was going to replace. Is this the driver side, before the cat?

Also now have PO300 - Random/Multiple Cylinder Misfires Detected which can I assume is related to my first problem and my car dying.

Will replacing the O2 sensor fix this?