What is the reason for the redness of automobile exhaust manifold?

There are several reasons why the automobile exhaust manifold is red:

1: Engine ignition time is not allowed. The ignition time is late, and the oil-gas mixture is discharged to the exhaust pipe without complete combustion. Causing secondary combustion of gasoline.

2. Three-way catalysis is blocked. It can also cause the exhaust manifold to turn red. Because the exhaust gas is not completely discharged.

3: The spark plug is not good, resulting in the cylinder not working. Then the oil-gas mixture is discharged to the exhaust pipe for secondary combustion.

Based on the above reasons, the engine power will decrease and the fuel consumption will increase. It will also cause engine jitter. Then solve the problem. Repair or replace.