I started to smell exhaust on Takeoff and purchased a Digital CO monitor. My mechanic found some deteriorating rubber boots around my Rudder Pedals and thought this might be the issue. We separated (but did not remove it since it would have required pulling the muffler and stacks) the clamshell Heater Shroud and could not see any issues. A few days later after installing the CO monitor I noted rising PPM readings off the scale (video attached) and removed the whole shroud and muffler to find a nickel sized hole next to the bottom opening for the exhaust pipe which is not visible with the Heater shroud in place (photo attached). I am now a huge proponent of digital CO monitors as $100 is worth the lives of myself and my family.
