Notes On Intermittents

Engine running, manipulate the oxygen sensor and ECM wiring and connectors while observing ECM Data ED32. If the fault is induced, ED07 will jump above 0.63 volts and the "OFF" status light will go on. Manipulate CKT 413 ground to the engine and look for a loose ground eyelet or ground eyelet installed at wrong location. Check oxygen sensor connector terminals for corrosion or foreign material. Clean if signs of corrosion are evident. If rich engine operation is suspected, perform PFI SYSTEM CHECK  . If the oxygen sensor circuit appears to be OK, go to PFI CHART A-9  to check for faulty or contaminated sensor.