A friend of mine has an 06 1500 silverado without his muffler and it sounds nice but im wondering if running it witout a muffler will do any damage to the engine. Also if its illegal to run without a muffler. So basically, whats your opinion on running a V8 truck without a muffler. I am keeping my cats on in whatever direction I go(Flowmaster 40 series, or no muffler).