any mod u do can void the warrenty. it all depends on how much of a **** the dealership feels like being. they can always some how relate it to an aftermarket mod you did to the car. so my best suggestion is to call ur dealership or go in and talkin to the service manager to see if the mod you wanna do will void the warrenty.I thought in most cases, unless its an engine component modification (im assuming like boost and not exhaust) you would will be ok as long as they cant prove it was that component that caused a failure.
DONT take this from me, this is just what I thought I heard.
This warranty applies to any accessory distributed by American Honda and purchased from a Honda automobile dealer in the United States, Puerto Rico, or the U.S. Virgin Islands.
Time and Mileage Period
Accessories Installed Prior to Retail Sale:
This warranty begins on the same date as the New Vehicle Limited Warranty (see page 9). All accessories are covered for the length of the New Vehicle Limited Warranty: 3 years or 36,000 miles, whichever comes first.
Accessories Installed by the Dealer After Retail Sale:
This warranty begins on the date the accessory is installed on the vehicle. All accessories are covered for the longer of the following two periods:
1) the time remaining in the New Vehicle Limited Warranty, or 2) 1 year or 12,000 miles, whichever comes first.
Accessories Not Installed by a Honda Dealer:
This warranty begins on the date the accessory is purchased from a Honda dealer. All accessories are covered for 1 year.
Honda will repair or replace any Honda accessory that is defective in material or workmanship under normal use. Honda will decide if an accessory will be repaired rather than replaced. If the accessory was installed by a Honda dealer, all parts and labor costs are covered. If the accessory was installed by someone else, the cost of all parts to repair or replace it are covered by Honda, but you must pay the labor costs.