Just wondering is going for 2.25" exhaust piping on a B18C civic (euro 1.8vti) with a K&N to big if ur planning to keep the car near enough stock. Was gonna get supersprint exhaust but this uses standard size piping so i can't see how it will produce a big improvement. At the moment thinking about getting a magnaflow universal backbox with custom 2.25 piping. Also wondering how would 2.25 piping connect to the cat which is standard size and if it can connect does this not create a bottleneck having a standard manifold and cat but larger cat back piping hencing making it pointless get 2.25" piping over stock