i was just wondering. a hooker catback for an lg4 car, is it still 3" I pipe with some kind of reducer to fit the stock cat or is it the same diameter as stock?

 

It is a 3" kit with a 2.25 reducer on the end of the I-pipe to mat eto your stock cat. If you are going with an entire 3" system right away, then buy the TPI application. It will not come with a reducer. If you are keeping the stock cat for now you will need the appropriate one that matches your car.