Thread: Need help with codes on 08 Pontiac GP 3.8L !!

Give us a brief description of each one of those codes. There's a lot of guys willing to share knowledge, but they're not going to do the leg work.

wow, how is it even running with that many codes popped?
P0306 misfire on cyl 6
P0054 Rear O2 heater circuit
P0102 MAF circuit low
P0141 Rear O2 heater circuit
P0412 AIR injection malfunction
P0418 Secondary air injection pump relay A -circuit malfunction
P0443 EVAP purge circuit malfunction
P0446 EVAP incorrect purge flow

I would bet there's a common power circuit here. First step is check all the fuses and replace the one that is blown. Then take a look at your #6 plug wire for a mark on it where it's likely laying on metal and arcing out.

Did a little wire diagram reviewing and everything you mention except cylinder 6 misfire has common power supply.
Powertrain relay #40 feeds two fuses numbered 10 (Emission) and 14 (O2 SSR) in the fuse box.

Check the relay/fuses above and that plug wirre and you should be all fixed up