You lost a tie rod.

Tow it to a shop, have them replace them all. Check the balljoints while they’re at it

First mistake was buying an Eclipse.

You can contact the buyer and tell them they need to figure something out as they didn’t provide a smog certificate less than 3 months old and they sold a car that couldn’t be smogged.

GL with that.

Did the mechanic tell you what the code was? How did he confirm that cat needed to be replaced?