Why Do Original Exhaust Manifolds Fail?
Exhaust manifolds carry exhaust gases from the engine to the exhaust system, and therefore have to withstand extreme temperatures. This will wear on any part, but poor design and inferior materials will cause these parts to fail faster.
As exahust manifolds wear out, they can crack and leak. As a result, the engine may become noisier, vehicle performance may suffer, and other parts may start failing as well if exposed to intense heat escaping from the cracked manifold.