Hi,
Dealing with a 2011 Buick Lacrosse 3.6 with Oxygen Sensor codes.
P0134 o2 sensor circuit no activity bank 1
p0134 o2 sensor heater bank 1 sensor 1
P0300 random misfires
P0301, 303, 305 cylinder 1, 3, 5 misfires
"bank 1" is cylinder 1, 3, 5 so I hope that the bank 1 oxygen sensor being bad...