Exhaust system in a car is a combination of several parts that create a medium for exhaust gases to emit into the air. The main components of the complete exhaust system are exhaust manifold, front down pipe, middle exhaust pipe, catalytic converter, dpf and finally the exhaust back box held together to the car with mountings, clamps, exhaust rubber mounting, exhaust sealant and exhaust gaskets.
Exhaust manifold is located on a engine cylinder head and when engine is running all the exhaust gases comes out into the exhaust pipes through exhaust manifold which puts the exhaust manifold under extreme heat changes, This continuous exposure of exhaust manifold to extreme heat causes cracks in the surface of exhaust manifold, the engine oil and coolant leaks in the vehicles also accelerate this process of cracking.
If you want to prolong the life of your car exhaust manifold then you need to check it frequently, if there is any oil or coolant dripping on the engine get it identified and fix as quickly as possible to prevent the further damage to other engine parts including exhaust manifold, DPF, EGT Sensor, turbo, egr valve and lambda sensor. If exhaust manifold is damaged, cracked or the exhaust gasket leaks than it will effect the performance of the engine including fuel consumption.
All car with gasoline and diesel engine are equipped with exhaust system to transport exhaust gases into the air, some cars with big engines with dual cylinder head have 2 exhaust manifolds and dual-channel for the exhaust gases.
Exhaust pipes runs underneath the car and are exposed to heat changes and rainwater and are prone to develop rust hence it needs continuous maintenance depending upon the environment. It's very easy to find out when your exhaust needs to be replaced by physical inspection if the exhaust pipe is rusted its better to change it soon as possible to avoid inconvenience as rusted exhaust pipe can break any time and if the exhaust pipe breaks the engine noise changes and it affects the performance of the engine, fuel consumption as well as caused noise pollution.
Exhaust systems are built specifically to withstand the high stress and heat conditions associated with engine exhaust however they are still prone to corrosion and rust over time due to weather conditions they are used in. If you suspect that your vehicle may be having an issue with an exhaust pipe or exhaust system, have the vehicle inspected by a professional mechanic to determine if the car needs an exhaust pipe replacement.