A major warning sign that mufflers need to be replaced is when they start to emit foul-smelling fumes. ... Any fumes that travel to the muffler will be funneled away from your car, however, if there is a leak or damage to your muffler, those fumes can easily get stuck in your car.

Is it bad to replace muffler?

Complications in your exhaust system can cause your engine to overheat or misfire. A damaged muffler can cause blockages in the system, which result in abnormally high engine temperatures or loss of power.

What happens if you don't replace muffler?

Your broken muffler can reduce the effectiveness of your exhaust system. The broken part can keep your car from being effective when siphoning the exhaust fumes out of your engine and will negatively affect your car engine's performance. In turn, your car will produce higher emissions and lose fuel economy.