The muffler is a metal canister containing baffles, chambers, or sound-absorbing materials that cancel out acoustic waves from the engine. As exhaust gases pass through the internal tubes, the sound waves bounce and destructively interfere, significantly lowering exhaust volume. It also creates a specific amount of backpressure, which must be tuned to maintain engine efficiency.
We need to weld in a new muffler because the old one rusted through at the rear seam.
A rusted-out muffler will sound like a tractor, but replacing it with a straight pipe will fail emissions and noise inspections in most jurisdictions.
Also heard as
- silencer
Related terms
Exhaust system
The piping and components that route spent combustion gases away from the engine.
Tailpipe
The final section of an exhaust system that vents combustion gases into the atmosphere.
Straight-pipe
To remove a vehicle's mufflers and catalytic converters, replacing them with empty tubing.
Glasspack
A straight-through exhaust muffler packed with sound-absorbing fiberglass.