Setting CO help needed
 

Hi guys,

How do you'll guys check your CO reading? From which tailpipe? If I were to set my CO at let say 3.5% with the probe/sensor in the left tailpipe and than when I put the sensor in the right tail pipe, it gives a lower reading. I guess this is because the right hand side of the exhaust is longer. So how do I set the CO? Isit from the left or right tailpipe?