House smells of sewage Please Help!

I'm with Joe on all points.

Excessive force on filters such that they warp in service strongly suggests insufficient return face area. Mark is right about ECM blowers - they will ramp up to oppose restrictions in supply or return system. Home unit ECMs are rated at 0.5 to 0.75 " WC, but I've seen them in operation at upwards of 2", and that pressure will warp a cardboard filter