WILL I MISS MY CAT

[Ape Est]

I mean my cat, of course.
I have a Nissan Skyline 350GT which I love but it's too quiet. Can anyone tell me if by replacing the middle pipe containing the cat and small middle box with a straight through pipe, will it affect the engine management?

[mr2-turbo-gar]

i would have thought that the ecu would have a self learning function, i could well be wrong though! so ive not really been much help, sorry!