Why does the Buick Envision suddenly have high RPM at low speed?

[Archer]

Buick Envision RPM fluctuation reasons are as follows: 1. Check idle switch: If the engine RPM doesn't increase when turning on AC or steering at idle, it indicates an issue. Adjust, repair or replace throttle position sensor. 2. Check intake pipe: Listen for air leaks in intake system which cause unstable RPM. Locate leaks and reseal or replace components. 3. Check exhaust system: If acceleration feels sluggish, it indicates exhaust system blockage causing RPM instability. Replace catalytic converter in this case. Solutions: 1. Check if catalytic converter is clogged and replace if necessary. 2. Inspect fuel injectors for carbon buildup.