Exhaust Flange Gasket
A high-temperature ring gasket compressed between two bolted exhaust pipe connections to prevent leaks.
An exhaust flange gasket is a high-temperature seal positioned between two bolted sections of the exhaust piping, such as where the exhaust manifold connects to the downpipe, or where pipes connect to the catalytic converter or muffler. These joints feature flat metal flanges that are bolted together; the flange gasket is compressed between them to ensure a leak-free seal.
Because exhaust gases are extremely hot and corrosive, these gaskets are typically made of reinforced graphite, wire mesh, or layered metal. Over time, the constant heating and cooling cycles, along with engine movement, can degrade the gasket, causing it to fail or blow out.
A leaking exhaust flange gasket will cause a loud ticking or blowing noise under the car, especially under acceleration. It can also allow toxic exhaust fumes to escape before the tailpipe and trigger check engine light codes if the leak is upstream of the oxygen sensors.