Other information:
Bring the engine to normal operating temperature. Connect
the Vacuum/Pressure Tester to the intake manifold. Run the engine at the
specified idle speed.
The vacuum gauge should read between 51-74 kPa (15-22 in-Hg)
depending upon the engine condition and the altitude at which the test
is conducted...
System Operation
Air Fuel Ratio Imbalance Monitor
The air fuel ratio imbalance monitor is an on board diagnostic strategy designed to monitor the air fuel ratio.
Air Fuel Ratio Imbalance Monitor — Heated Oxygen Sensor (HO2S) Monitor
The air fuel ratio imbalance monitor estimates the cylinder to
cylinder air fuel ratio difference using the universal HO2S
high frequency signal...