yeah, tps is is the throttle position sensor. its located on the throttle body at the front as you look at, black plastic connector, never hurts to check them either, as there prone to failing on V6 2.5's. id defo check your plugs aswel, if its had new coil pack and leads, which are also prone to failing, chances are, its had plugs aswel, becasue when they develop a missfire, its cheapest to expensive, so usually people start by changing the plugs, then leads, then coil pack, but it never hurts to check them, as they have long life plugs, so they last a while, and changing the back three isnt the easiest job unless you have rite extension bar and wobbley socket, so there overlooked a lot of the time.