I need a passenger side front strut on a 2009 Toyota corolla. Do I always change them in pairs or can I just change one? Also do I need to align the front end ? Richard whiskey

We recommend pairs,If you have over 60k miles.It should be aligned after struts and steering angle reset.

If the strut is being replaced for physical damage, you can replace just one but if it's worn, I would recommend changing both. Alignment needs to be checked after replacement.