Note On Intermittents

With engine running, manipulate oxygen sensor, PCM wiring, and connectors while observing PCM parameter ED33. If fault is induced, ED33 will jump to greater than .63 volt, and ECON status light will illuminate. Manipulate circuit No. 413 (ground to engine), and look a loose ground eyelet or ground eyelet installed at wrong location. If oxygen sensor circuit is okay or lean engine operation is suspected, perform PFI SYSTEM CHECK.

Fig 1: PCM Code EO43, Schematic, Left O2 Sensor Rich Signal

Fig 2: Flow Chart, PCM Code EO43, Left O2 Sensor Rich Signal