Swapping out the muffler on an NC Miata is a lot easier than you think!
All you need is an impact wrench, a deep 14mm socket, pliers, an adjustable wrench, a socket wrench, soapy water, and some lubricant. Step 1: The day before swapping out the muffles, you want to spray down the two bolts connecting the muffler with either some wd40 or Liquid Wrench Penetrating Oil. This is will make taking off the bolts the next day a-lot easier! Step 2: Undue the two bolts holding down the muffler, if there difficult to take off with a socket wrench then use an impact wrench. Step 3: Lubricate the muffler hangers with either soapy water or some lubricant. Then following the instructions in the youtube video, gently pry off the hangers one one side one by one. Once you have one side off, switch to the other and repeat. Wala its that simple! Step 4: Take the new exhast and mount each side one at a time back on the muffler hangers. Take your time to securely mount them. Step 5: replace the old muffler gasket with the new one. Step 6: Carely allign the muffler and tighten back both sides evenly at the same time. Step 7: After starting up the car, check for leaks by pouring soapy water and looking for bubbles. If you see bubbles you have leaks and need to adjust and tighten the muffler. If you don’t, congratualations you all set!
Here’s a comparison video of the stock muffler vs no muffler vs a Cobalt performance muffler!
Overall, its not a very difficult job to do. took me about an hour and half. Adding an aftermarket exhaust is one of the best mods you can do to NC Miata, because the cars come wayyyy to quiet from the factory!