thanks for the info. so u saying that any dual port headers will fit mine even though its made for an 2.5RS or 2.2? i'm not really looking for power. i just want better breathing(better gas mileage), sound, and looks. cost too much for better engine swap. i rather get and original RS coupe or and STI if i was looking for real power, but it'll cost me 5 times more than this ej18. about the dual port header, does it bolt up onto the cat converter flex or i need another customization to bolt the rest on? please keep replying. i'm still a newbie.. thanks for your reply.