Everything I read tells me I need a 17mm socket.
I had a cheapie torin jack and couldn't get the car on stands, but I could see the bolt and filter so I gave it a try. (unsafe I know)

I put a 17mm socket on it and it did not want to fit. My stupid socket set skips 18mm and goes to 19mm.
I put on the 19mm and there was way too much play.

Is it a 17mm or 18mm for the 04 6mt?

Won't try it again till I get a proper jack, but wanted to know if it's normally a 17mm on this car.
It didn't want to fit, so I'll be getting a 18mm just in case somehow it really is an 18mm

 

Should be 17mm unless someone else has replaced the OEM plug with something else in an attempt to repair damaged threads. I have encountered some cheaper tools that are sized incorrectly and are too small to fit, and this may be your issue. I don’t think Acura/Honda uses 18mm for anything.

 

I can see if maybe the socket is sized incorrectly. This socket set has been working for me so far, it's a stanely set. I even reached for a SAE socket and got the same result. would not slip on and too much play.
the "17mm" wasn't an issue of covering and spinning, the nut was not going in, I kept spinning it to get it to seat. Heck oddly enough , this set doesn't have a 18mm or sae similar.

I do kinda suspect somebody along the way replaced it with something else if the 17mm is not fitting.

 

I'm pretty sure my socket is not the wrong size. I can see some oil wetness at the bolt. It starting to look like it was stripped and whomever along the way decided to thread it with a larger bolt. Pretty dam sure it's a 18mm bolt there now on my drain.