Subfloors play an important role in manufactured and mobile homes. It is especially critical for homes that still have particle board subflooring, as they will likely need to be replaced eventually. Particle board is made of tiny wood particles that are glued and pressed together in 4" x 8" sheets. It is a strong material but it soaks water up like a sponge and is NOT suitable as a structural subfloor.
Freedom Vapor Barrier will assess your current subfloors and provide a free quote to replace them with much more secure and long-lasting materials.