Test H: Step 21
21) Check For Power at HEGO Harness Connector With KOEO, and HEGO disconnected, set DVOM on 20-volt scale. Measure voltage between KEY POWER circuit and PWR GND circuit at HEGO vehicle harness connector. If voltage is greater than 10.5 volts, HEGO system is okay, go to step 1) of this test (except sequential PFI engines). On vehicles equipped with sequential PFI engines, fuel delivery is okay, HEGO sensor may have cooled prior to KOER Self-Test. If a driveability symptom persists, fault is in an area common to all cylinders such as air or vacuum leaks, fuel contamination, EGR, MAP, etc. For all vehicles, if voltage is less than 10.5 volts, go to next step.