Note On Intermittents
WARNING: This page is about a different car, the 1992 Cadillac Fleetwood and 1992 Cadillac DeVille. However, it is still accessible from the selected car via links, so may be relevant.
With engine running, manipulate O2 sensor, PCM wiring and connectors while observing PCM parameter P.1.4. If fault is induced, P.1.4 will jump to less than .37 volt and ECON status light will go off. Manipulate circuit No. 413 ground to engine, and look for a loose ground eyelet or ground eyelet installed at wrong location. If lean engine operation is suspected, perform PFI SYSTEM CHECK.