So I started up my 09 Civic during this brutal cold (was around 18 degrees) for the first time in about a week. The starting was really sluggish, as if the battery was dying, I was shocked because this battery is relatively new (about half a year old). Once it caught, the idle shot up like a rocket ship far higher than it normally does before coming back down quickly. Made me cringe thinking of the wear it did after not having the car run for a week. As I was stopped at a red light, it spontaneously started making a really loud ticking noise. This was not a normal sounding fuel injector ticking. It was so loud I could hear it clearly outside with my window rolled down. It didn't seem to change with the RPM as I took off, but driving would drown the ticking noise out completely, then I would hear it again as I slowed down. Eventually after driving a while the ticking sound went away. I even turned the car off and back on a few times and I never heard it again the rest of the day. Does anyone have any idea what that was? I'm concerned something broke. I did put fuel treatment in a month ago and this is the same tankful of gas with the treatment in it. Not sure if the treatment messed with the fuel and it didn't play well with the temperature. I know the car shoots up idle by probably dumping fuel to start in such cold weather. Not sure why the idle shot up so high though and why it started making a ridiculous ticking sound that it hasn't made in the five years I've owned it.