Ever since I had my cutout installed, if the car has sat over night or for long periods of time, especially when it rains or there is a lot of moisture in the air, is will make a poping backfiring noise when shifting gears (not real bad, but noticable). After a little while of driving it doesnt do this anymore. I leave my cutout open all the time and was just wondering if this is normal?

 

Yeah,thats normal.Mine does it too.It runs richer when cold.The excess gas is igniting in the exhaust.