i have a 1994 pontiac boneville se and when we drive it the check oil light and check engine light
comes on and the car shuts off while driving and after sitting for a while starts back up. we were thinking it could be the pcm or the ecu? could anyone help.

*** Moved to its own thread - Kevin ***

Which happens first

You notice the lights or you notice the rpm? I'd venture to say it'* stalling which kicks on the lights.

Suggested items would be:
Check for any codes stored in the computer.

Check all battery connections for corrosion and good connectivty.

Crank sensor replacement

PCM replacement.

The PCM can it be easily accessed? And Where do you think I could get one from?

Sounds like you might be aiming to shotgun a pcm.

Your pcm is located under the dash on the passengerside.
Remove the black plastic hush panel from under the dash. Looking at where the carpet ends there is a flat sliver case with red white and blue connectors. That'* the pcm.

When swapping you need to remove the access panel on the pcm and swap the blue chip into the new computer.

I have found replacements at auto parts stores and junkyards.