Probably a really dumb question but here goes. I bought a 1998 honda prelude from a guy and when he sold it to me he said it would need a new oil pan gasket. However, when I pulled the pan to install the new one there wasn't a gasket there at all. Well now I put a gasket on the pan and it seems like it is leaking more. There is supposed to be a gasket on the oil pan correct? Or no....
Cast pans use Hondabond (liquid gasket) as a sealant, as well as a crescent or "half moon" seal in the recess just beneath the rear main seal (transmission side).
The only pans that use an actual gasket are steel pans, which are commonly swapped but sometimes require a different oil pickup as some are deeper.
97-01 Preludes with an H22a4 came with a cast pan.