1989 Astro problems

WAG [wild ass guess] is an emissions sensor. There are a few and i'm unfamiliar with all of them. I think there's a 'throttle position', a 'MAP', an 'idle mixture', etc. But a slightly less WAG is the oxygen sensor down in the header pipe. About $20 4 months ago.

Hopefully an emissions guy will read this and post. It's almost worth a $20 gamble and easy to change and works in a bunch of other gm vehicles if it's not.