Originally Posted by
MattyB1983
The diagram is wrong, there are only 2 cats.
The up pipe has a cat in.
Downpipe has a cat in.
Middle section has a resonator box.
Then the rear box.
The diagram is correct for UK newage impreza (4 piece exhaust).
Classics are different.(3 piece exhaust) and they don't have a pre-cat in the up pipe.
The resonator in a classic mid pipe can sometimes be a cat (depends on destination)
