I do think that the PVC pipe will get soft when the heat from the exhaust goes through it.I have a genturi but my onan is a juice box model. I had a friend make up an exhaust extension and he used stainless steel to make it. It bolts to the exhaust outlet under the juice box, then goes to the genturi which I attached to the rear ladder so it would go up and over the 5er. I never ran the onan at night. The juice box is portable and attaches to a rear hitch on the 5er. You have a different setup than mine but it's an idea for you. Good luck.