Note On Intermittents
WARNING: This page is about a different car, the 1992 Cadillac Seville and 1992 Cadillac Eldorado. However, it is still accessible from the selected car via links, so may be relevant.
With engine running, manipulate O2 sensor harness, 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 glow. Manipulate circuit No. 413 (ground to engine), and look for a loose ground eyelet or ground eyelet installed at wrong location. If O2 sensor circuit is okay or lean engine operation is suspected, perform PFI SELF-DIAGNOSTIC SYSTEM CHECK .