I have a question if i install a p2r spacer and a cai would i have to buy a better exhaust?or can i stay with my stock

 

i don't think you'd have to buy a new exhaust

 

Stock would be fine.

 

headers and cat would help more than an exhaust, but they are not necessary either

 

The P2R throttle spacer will not lead you a day and night different which means no need for an exhaust to accompany But if you are planning to get Header/ High-flow Cat/ Pulley and all other bolt-on down the road, then why not?

 

The exhaust is not a big power upgrade on this car afaik.....it will help once the other stuff is done for sure...but you got a ways to go before the exhaust is going to be a worthwhile expense for power. Now looks and sound....you may want an exhaust for that!

Marcus

 

The exhaust is not required to do an intake and TB spacer. At most you're going to get 5 HP from an exhaust on a TSX that is NA. You might see 10 HP with a S/Ced TSX from the exhaust.