need help with trouble codes

i have a 2000 dakota quad cab with 95,000 miles on it. it has a 3.9 with an automatic tranny. i have codes p0300, p0301, p0305, and new code p0138. i have replace cap and rotor and plugs. what would make the left bank misfire on those 3 cylinders. has me scratching my head. need some more heads thinking of what to look for. thanks for your help.

Could be the plug wires or something with the fuel system. Like the injectors or the fuel rail.

300 is multiple cylinder misfires. 301=misfire cylander #1, 305=misfire cylinder #5, 138=S2 Sensor Circuit high (Blank1 Senor2)