Was there ever an item besides L-Rods that could use the L-Rod Exploration skill? i remember at one time i was able to but i dont remember what it was
There are; both the Sun Road Colt and Sun Prophet Colt can be used as L-rods.
The original L-Rod, the L-Rod that use action maker in connous and physis, the human versions of those L-Rods, and as thunderbro said, the two guns that are also L-Rods.
What you may be thinking of is using the demigod skill Awakening of Light, while transformed into demigod, you automatically uncover any nearby artifacts like you manually used an L-Rod, but passively.