I have maintained my own vehicles for over 25 years. That includes EVERY oil change. I've NEVER taken my cars or trucks in to a shop for an oil change. Or an ATF change. Or a coolant change. Yeah, I take pride in that.
Needless to say, the drain pan that I have had over 20 of those years has seen a lot of fluids go through it (and ALL of it recycled properly). It is still going strong, but the threaded plugs are in sad shape.
When I saw Prefab's "OIL DRAIN PAN REPLACEMENT PARTS" (https://www.thingiverse.com/thing:1554884), I was excited. Finally a set of replacement plugs! Unfortunately, they didn't fit my pan. Then I saw scottandpamela's "Oil Pan Drain Plug" (https://www.thingiverse.com/thing:3710911). Those threads didn't fit either, but the conical part was a match. But scottandpamela mentioned using Tinkercad, so I went there to see if I could create threads to match my drain pan. A little fussing about, and after grafting scottandpamela's conical piece to my new threads, success!
Look at the pictures. If you have a drain pan that looks like mine, this plug MIGHT work for you. For me, it was third time's a charm.
I used PETG and it worked. Any rigid filament should be fine.