My yaris drives to the side very easily

[MyYaris(:]

Hi, I'm sorry if there is a topic already about this. It's hard for me to explain but please stick with me and help if you can. I dont know much about cars.

I had my yaris for less than a year and I always noticed that it's hard to drive it centered..... like it goes to the side VERY EASILY??! especially on the highway. I drove my mom honda civic and noticed how more stable it is. I've been on this website, Yarisworld, before I bought my car and I remembered a Topic about this, and something was used to fix this, something put in the car under the hood??????
I looked through pages and can't remember what it was called.


I'm 19 yearold girl and I drive very far to my university and will again this august. I want to get this fixed because I had some close calls.

Also if you have any other advice on how to take care of my car (other than oil changing and tire rotation) like the basics, please do so[:


Other than that I love my yaris(:

Hope you can help! thank you!