How to Replace the Muffler on a Chevy Impalaby Contributor
The Chevy Impala has enjoyed three runs with the GM corporation from 1958 to 1985, from 1994 to 1996 and from 2000 to the present. This full size car may have a single pipe system or a double pipe system, which is important to know when replacing the muffler. If you find holes in your muffler or it starts making loud noises, then it's time to replace it.
Spread out an old blanket or a large piece of cardboard on the ground to lay on as you replace the muffler. For an easier time repairing, you might consider jacking the car up and placing it on jack stands instead.
Purchase a new muffler. It must have a 2.25-inch center inlet/outlet, be 4 inches thick by 9.75 inches wide, and 13 inches long. Make sure it is the right one according to the model year of your vehicle.
Look over the old muffler. Spray the fasteners generously with a penetrating lubricant before you loosen them. The penetrating lubricant will help you to remove the screws and bolts with ease.
Loosen the bolts at the bottom of the muffler strap. It's okay to let the muffler hang. Using a hacksaw, saw the stock muffler completely off of the pipe, leaving 1 inch to 1 1/2 inches of straight pipe at the muffler inlet, if you have a single pipe system. Alternately, if you have a dual pipe system, take of the U-bolt clamp found on the front of the muffler and remove the muffler from the exhaust pipe.
Take of the tailpipe clamps and then remove the tailpipe. After taking off the muffler and tailpipe, inspect all the hangers and replace any that are damaged.
Put the muffler into place under the vehicle. Make sure the muffler inlet slips over the exhaust pipe with ease. Put sealer on the connecting surfaces and then straighten the muffler over the pipe. Tighten the muffler clamp on the muffler inlet using a flathead screwdriver and then tighten all clamps starting at the front of the muffler and working you're way back.
Lower the car, start the vehicle and carefully inspect the muffler for leaks and loud sounds. If there are any, you'll need to tighten the bolts more. However, the clamps should be loose enough to allow the muffler to move a little with the movement of the car.