After work intended to address an idle speed that rises and falls, repeat the original conditions in a safe place and check whether the symptom returns. Note whether it happens cold, warm, with the A/C on, or after selecting Drive. Record the result before clearing codes or resetting adaptations.
Follow the maker’s procedure for drive cycles and readiness monitors. Check for intake leaks, a sticky throttle path, and recent work around the air duct. If the issue remains, return to the evidence instead of swapping another part.
Quick educational note
For information, not a diagnosis or repair instruction. Vehicle-specific checks are still required. Consult the manufacturer's guidance and a qualified technician.
How to use this information
This article explains general principles and does not establish what is wrong with your vehicle. Read the content limitations.