Note On Intermittents

With engine running, manipulate oxygen sensor, PCM wiring, and connectors while observing PCM parameter ED32. If fault is induced, ED32 will jump to less than .37 volt, and ECON status light will go off. Manipulate circuit No. 413 ground to engine, and look a loose ground eyelet or ground eyelet installed at wrong location. If lean engine operation is suspected, perform PFI SYSTEM CHECK. If oxygen sensor circuit seems to be okay, go to CHART A-9, OXYGEN SENSOR DIAGNOSIS.

Fig 1: PCM Code EO42, Schematic, Left O2 Sensor Lean Signal

Fig 2: Flow Chart, PCM Code EO42, Left O2 Sensor Lean Signal