How to Install a Flowmaster Muffler

When you install a Flowmaster muffler you're looking for power and torque gains as well as the renowned Flowmaster sound. Flowmaster mufflers are available in models that raise the exhaust sound only outside the vehicle or for the hardcore driver, a muffler that resonates in the cabin is also available.

Things You'll Need

  • Flowmaster muffler kit
  • Jack stands
  • Cutting tool
  • Wire brush
  • File
  • Screwdriver
  • Verify the size of your current exhaust and order the matching size to avoid needing converter pipes. If converters are necessary purchase them along with your new muffler.

  • Raise the truck enough to work comfortable on the exhaust. Place an additional jack stand under the old muffler to hold it firmly in place.

  • Measure the new Flowmaster exhaust and subtract 4 inches. This gives you the required size of the cutout, taking into account the additional pipe you'll need to make the connection into the old exhaust. If you're going to install your own extension pipe make adjustments as required.

  • Mark the cutout points carefully and cut the old muffler out with the cutting tool of your choice. Clean any rust or grime out of the exhaust with a wire brush and smooth the connecting ends with a file or sandpaper.

  • Support the Flowmaster muffler with a jack stand, insert the exhaust onto the intake side of the muffler leaving the clamp in place but loose. Position the old pipe or extension into the muffler on the exhaust end.

  • Install any hanger clamps that were included with the muffler before you tighten the exhaust clamps.

  • Start the engine and quickly check for exhaust leaks, if you find any you can weld the seams on fittings that are loose.