Can I get some input on putting a cat back on my 2014 LT. I talked to the local mechanic and he said leave the stock piping because it is stainless. He will then cut out the muffler and weld a pipe straight out the back and add a tip. I want the res cut out also but he suggested I make that decision after the muffler is out because it will be louder. I like the turbo spool sound and the low grumble without the resorator or muffler, but how loud will it actually be and I've only seen videos that show low rpm ranges of straight pipe cat backs. I'm leaving in the cats due to state inspection.