So I have the joy of a continually reoccuring MIL for codes 0300, 0303 and 0304 (as well as 0420, different code, Cat efficiency low). I see that a LOT of people here are throwing misfire codes and I am wondering (more specifically from the LNF guys) if you found the cause or a solution to the codes coming up. I have an Interceptor on order so I'll be better able to trace the time that the engine is misfiring, but for now the dealer claims "No misfires detected while in the shop, checked the spark plugs for carbon tracking and found none." They think I should remove my remote starter to try to remedy this, which I think is bullshit because whether I use the remote or a key, I'm letting the car idle for a bit when it's -20*C. I can't think of a single possible reason the starter would cause the car to misfire either, it's basically just a replacement for the key, it shouldn't alter fuel trims, firing order or timing, etc. I pulled the battery cable once and the MIL came back, and I had the codes cleared twice after and the MIL has come back within 3 days every time.

*If it matters my car is a 09 SS with about 19,000km's on it right now...seems too early to keep throwing codes. It first started throwing them after a REALLY cold spell and I tried to start the car below -35*C. It took about 6 tries to get it started and it ran REALLY REALLY horrible (misfiring, smelled like pure gasoline INSIDE the car, sputtering and no power under acceleration until it hit 78*C operating temperature and has been fine since). *

Any suggestions here?