Water leak on passenger side floor

Carpet wet! drain tube blown out with 125 psi and 10 inch plastic wire inserted to clear out any debris that might have been in there! fixed? NOT!!! still leaking!! pulled carpet back,ran A/C for a few, waiting to spot this elusive leak… finally I saw the drip,drip,drip coming from the end of the evaporator housing where it meets the firewall. What is the easiest most inexpensive fix??? please help!!! thks

I would try using some silicone to patch the leaking area.