Title: Inspect throttle body, air induction system, intake manifold, and gaskets for vacuum leaks and/or unmetered air.
Course: Automotive Technology III (20104-III) > Section: Engine Performance: Fuel, Air Induction, and Exhaust Systems Diagnosis and Repair

Procedure should include

- using a scan tool
- monitoring data and comparing results to service materials and manufacturer guidelines
- performing a propane test, if necessary.

ASE Education Foundation
2017 Automobile Service Technology (AST) Level
VIII. Engine Performance
D. Fuel, Air Induction, and Exhaust Systems Diagnosis and Repair
Task 5

Process/Skill Questions:

- What is unmetered air?
- How will unmetered air affect air-fuel (stoichiometric) ratio?
- How will a vacuum leak affect idle speed?