Common modifications to a Toyota 4Runner include adding nerf bars and running boards, changing differential gear ratio, adding aftermarket grilles and bull bars, suspension modification and upgrading the exhaust system. Modifications for the Toyota 4Runner range from simple accessory and cosmetic changes to projects requiring extensive mechanical work.
Adding nerf bars, running boards or bull bars are relatively simple modifications for the Toyota 4Runner that enhance the look of the vehicle and provide some functional benefits for off-road driving and for entry and exit of lifted vehicles. Suspension and exhaust modifications help to increase driving performance and power and require a fair amount of mechanical work. Changing differential gear ratio is mechanically intense and can help maintain power for vehicles with oversized tires.