I drive Toyota Highlander 2005. It's a gasoline car. I filled up the tank a few days before this happened (right before Halloween.) It then sat in my garage for about 3 days. (I live in the WA sate and the temp at night was close to freezing.) I then needed to drive it yesterday and when I started it up, a black plume of smoke came out from the exhaust. After that happened, the engine has been running fine.
How would you explain it?