Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.
In my nearly 30 years of wrenching I've never seen a factory OBD1 GMT400 with a 3 wire O2 sensor. I'll take your word that they're out there, perhaps in Commiefornia, but I've never seen one.
And I have a Cali emissions equipped '95...