What are the consequences of engine valve air leakage?

Consequence of air leakage from engine valve: 1. Air leakage means that the air intake of the engine enters the air intake without passing through the throttle valve or the air flow sensor, the former will lead to abnormal idle speed, and the latter will lead to abnormal signal; 2. In the former, the normal engine speed is controlled by the air intake of the throttle valve replica. The more intake air, the higher the rotational speed (the fuel injection quantity is calculated according to the intake air). If the air doesn't pass through the throttle (exposed), the throttle replica can't control the air intake; 3, so the idle speed will be high. However, this part of the air does not pass through the air intake detection sensor (flow rate and pressure), which leads to inaccurate signals reflecting the real air intake and will also affect the exhaust, so the exhaust will also exceed the standard at this time.