It appears that the horizontal passthrough pipe has a "left" and "right" part here. I am not entirely sure how the program I was using works, as there is little documentation on it, but I am currently in bank 0x01 of tiles in tileset 0x08 and the tile 0x01 and 0x02 both appear to be part of the horizontal passthrough pipe. I know Smaghetti is archived, but this was really bugging me to submit it. :)
It appears that the horizontal passthrough pipe has a "left" and "right" part here. I am not entirely sure how the program I was using works, as there is little documentation on it, but I am currently in bank 0x01 of tiles in tileset 0x08 and the tile 0x01 and 0x02 both appear to be part of the horizontal passthrough pipe. I know Smaghetti is archived, but this was really bugging me to submit it. :)