Chauncey's was never a dive bar in my opinion, but dude is looking for dive bars.
There used to be a great dive bar in Cranberry called Marty's Suburban. 25 years ago I worked 11-7 and would go there after work...and get absolutely smashed by noon lol
...but that's not Pittsburgh proper.
Let's see - there's a dive bar in McKees Rocks (no seriously lol) called Michael's Lounge. Great wings, cheap beer and always a few hoodrats smoking cigs at the bar. Tucked away on a side street. Pretty cool place actually.
Also, the Obey House (pronounced oh-bee) Tavern on stueben street in Crafton Heights. Good food too.
I also found this on the interwebz - I'm pretty sure a couple of them didn't make it through the pandemic (Hambones is no longer open) but this is a good starting point for the local dive bar scene
https://www.thrillist.com/drink/pitt...-in-pittsburgh
Take a pack of newports with you and you'll be an instant hit with the hoodrats ;-)