I have an '07 Chevy Malibu, whose turn signal doesn't seem to disengage whenever I make a turn, unless it's more than roughly 160 degrees (a U-turn). What are some of the possible causes and are there any easy solutions, as this is quite annoying to both me and the drivers behind when I forget to manually turn it off?
I don't know that car specifically, but it sounds like the auto-cancel mechanism is bent or mis-installed. Since it is integral with the steering column, you will probably need to pull off your steering wheel and get into where the switch mates with the column. There will be a plate or ring on the column with a tab or the like that will move a lever in the indicator switch when the wheel is turned.
I've seen this ring installed upside down in an old Porsche with an aftermarket steering wheel. The indicator wouldn't cancel because the tab was in the wrong place. Turned the ring over, put it all back together and it's fine.