I have the same problem with the 2-piece Y trap on the exhaust fan outlet.
I just replaced the Johnson Ctrls IPI with a Honeywell kit and noticed the
source of the leak while testing. The 2-piece trap was sealed with a silicone
RTVish product that did not adhere. The bottom of the burner control enclosure
is very rusty, especially near the power input connector, and there is moisture
in the air handler too. I suspect that is the most serious health concern. Any
mold supported by the wet environment is past the air filter and will be distributed
throughout the house.
I can believe this has not been a recall issue or that the part costs $95! Maybe I'll
redesign it myself. Any more problems with this unit and it is ready for the heap.