What is the reason why Subaru exhaust burns eyes?

The pungent automobile exhaust can be divided into two situations:

The situation is that the gasoline is not fully burned and the tail gas caused by too much mixed gas is pungent.

There is oil burning in the car. There may be many reasons for insufficient combustion of gasoline. For example, problems in any part of the fuel system, ignition system and air intake system may lead to insufficient gasoline combustion. Such as abnormal throttle opening, abnormal throttle, etc.