P0305 is cyl 5 misfire and P0205 is injector 5 control circuit. I would assume that the problem should be fixed under the warranty. I'd take it to the dealer. And I wouldn't beat on it until the problem is resolved.
Nadia - 2010 Camaro LS3 2SS/RS - SLP Blackwing, K&N Air Filter, SLP Under Drive Pulley, VMax TB, OBX 1-7/8 LTs with HF Cats, OBX 3" Cat-Back, Custom Predator Tune!!
Esmeralda (03 Mustang GT) - UDP, CAI, PP intake manifold/plenum/75mm TB, 4.10s, built/upgraded trans w/ Transpak, 2400 stall converter, full exhaust, 255 LPH fuel pump, Sniper tune!!