I have a tub spout with a diverter the diverter has to remain up or else I will leak down my basement. Now it leaks every time after a shower. Help

You need to replace the diverter

i have a tub spout with a diverter the diverter has to remain up or else i will leak down my basement. now it leaks every time after a shower. help
I'm no pro, but it seems to me that you mean the diverter must stay down (the spout thus being open). When the diverter is up, the shower comes on. The problem may be the pipe which connects the tub spout to the faucet assembly. When the diverter is up, water is diverted to the shower head, which raises the pressure somewhat on everything below it. An item which might leak only slightly would leak more aggressively when the diverter is up. At any rate, that would be my first move.