What is the sudden increase in the idle speed of the car?

Three-way catalytic failure, users are advised to replace the three-way catalytic device.

The sudden increase may be caused by the failure of the vehicle throttle. Too dirty throttle will lead to the error of throttle opening, the sensitivity of throttle will be reduced, and the throttle may not be closed normally at idle speed, resulting in a sudden increase or even more than 3000 rpm.

Precautions:

Contrary to fuel consumption, the lower the idle speed, the more obvious the dilution effect of exhaust gas, which means that increasing the idle speed is beneficial to reduce CO and HC emissions. Relevant data prove that when the idle speed of automobile engine is increased from 700 rpm to 800 rpm, CO decreases by 10% and HC emission decreases by 15%.