Hi.. I have a uk turbo wagon and have just took a gamble and purchased a used 3 inch cat back exhaust and wondered if it will mate up to my standard cat... Or do i need to get some sort of reducer fitted... The exhaust came off of a v4 and the guy said it mated straight to the standard system on his car... Thanks

 

Some 3" systems do narrow to 2.5" bore. Post a picture of the pipe. He will have either used a reducer piece or it will narrow to 2.5" bore.