When I asked the Subie parts people about the drain plug they said it had the temp sensor built in... am I missing something here? Is this a different drain plug than the one on the oil pan? It may be 19mm but I'm sure it's no bigger than that if it's the normal oil pan drain plug.
Please let me know what's up, I've never heard of this and I'm always eager to learn new things
If your looking for a wrench to fit the drain plug with the oil temp sensor, I believe it's 27mm. I'll go home and look at my wrench to be sure and repost the definite answer. I had to look in several different stores to find a wrench that big, finally I found a Sears that had them in stock.