Water Sputtering noise Lennox furnace

I have an old Lennox furnace. Error code is giving me the following error: Pressure switch open with inducer on.

When the furnace is running it is making almost a water sputtering noise from right around/ behind the circuit board. Very similar to when you just turn a hose on and it’s half air/ water being pushed out the hose.

I’ve never noticed before either? Does anyone know what this could be?