What are the reasons for slightly high car idle speed?

[DelVanessa]

The reasons for slightly high car idle speed are: 1. The idle switch does not close; 2. The idle control valve is faulty; 3. There is air leakage in the intake pipe; 4. Incorrect valve timing; 5. Fuel injector dripping or clogging; 6. Exhaust system blockage; 7. The EGR valve opens during idle conditions. Solutions for slightly high car idle speed: 1. Adjust or replace the throttle position sensor; 2. Clean or replace the idle control valve and use a decoder to perform basic idle speed settings; 3. Locate the leakage point, reseal or replace related components; 4. Check the timing marks and readjust the valve timing according to standards; 5. Clean and check the fuel injection quantity of each injector to ensure there is no clogging or dripping; 6. Replace the three-way catalytic converter; 7. Remove carbon deposits on the EGR valve or replace the EGR valve.