I am buying a new 2003 civic si coupe (5spd) in the upcoming spring and i was hoping to put a few mods into the engine to upgrade its 127hp sohc 4 banger. The only problem is i want to keep the warenty valid on the car. Is there anyway to modify the engine but at the same time keep the warrenty valid? Also, any suggestions for mods would be helpful. Looking to get the most hp/ torque boost for the buck.