For those of you wondering, just deleting the muffler won’t make it loud. You will get a nice sound at higher RPMs. However at idle and lower RPMs it will be quiet. The muffler really doesn’t muffle much of the sound like it does on other cars. On an IS300, it’s the resonator that quiets most of the exhaust sound. So if you want a decent sound but not too loud, you can keep the OEM muffler and delete the resonator. I thought it was still too quiet deleting just the muffler. Deleting the resonator and muffler it is loud at all RPMs. Now you have 3 different sound levels to choose from. Enjoy!