Contour Enthusiasts Group Archives Forums General Troubleshooting engine runs rough

So I started my csvt today after it sat for about five days. Upon start up it sputtered for about five seconds and as soon as I stepped on the gas it went back to normal, ran like a champ. I know I need to replace one o2 sensor and I was going to replace the spark plugs also, other than that all of the maintenance I believe is up to date. Does anyone know what might cause this to happen because I'd like to kill the problem before it possibly becomes something worse.
Thanks in advance for any input on this issue.

I sure would not worry about it yet. Getting a bit loaded up on a cold start is not really unusual. It is especially common if you only ran the engine for a short time on last shut down. Short time, such as back it out of the garage and then shut it down.