Anyone removed the splendide combo from an older Fleetwood?

My trap was empty from not running the washer in quite some time but neither that nor the vent valve were my problem. The smell was coming from the large hole behind the washer that lead to the underbelly. It sort of smelled like something died down there. I just spray foamed the hole. I also cleaned the 15 years of dust and gunk that was back there and found a hand mirror from who knows when.