question about down pipe

i got a 40 series flowmaster today it sounds good nice deep sound and a nice ide. anyway when i was at the shop the guy said that i had a 1'8 in pipe from the headers to the cat and a 2'in pipe from the cat back is this the same on every cavalier or did the old owner do something siupd. its a 96 sedan with the 2.2l engine.

When i changed my downpipe it was 2'' just as my exhuast but of course i could be wrong cause i didnt measure it. Well sorry i cant help but i think it should be the same as the exhuast.

the piping should be uniform all the way back, the person before you may have had the exhaust replaced somtime before you got the car.