Has anyone ever thought of using rubber marine exhaust? I know temp. is a problem but how hot is the exhaust after the down pipe? The **** is made to be used with water but um, we have none, so, does it cool down to say 300 around after the dp because I know it isn't 1100 at the back of my muffler so it must cool somewhat but how much? What temp. does the second o2 sensor have to work at? Any ideas are great.