I have a 97 accord f22b2 and the exhaust is rusted entire thing except muffler since I replace the old on when it had holes, question is what size pipe should I do? If I upgraded size how much power increase should I expect? I'm thinking maybe 2.25 or 2.5 inch pipe all the way, what size is recommended? Wanting better sound power and mpg

 

2.25" if you are stock. Without any other mods you really aren't going to get anything more than sound and maybe some increased throttle response. MPG will remain the same as long as you can stay off the throttle.

 

Will be upgrading over time starting soon, if I did 2.5 I wouldn't lose power would I? Heard if you go to big with egr you can