boppagibbz

I have a 98 v6. After driving a little bit the check engine light starts flashing and it starts missing. I changed the plugs and wires and it still does it. Before I go and buy a new coil pack I'm going to list the codes it's throwing and see what people think I should do:
P1151
P0171
P1443
P0302
P0306

Also, I just recently changed the harmonic balancer and put a used one from the junk yard back on it but I don't know if that could cause the problem. I'm not much of a mechanic at all.