But here in Nevada, there&39;s something you can do about it. If the hoses are hard and brittle, you should replace them. Smog Check 101 What This Test Is All About. Dang smog, thats comin along nicely. This monitoring is essential for ensuring smog check success, as it will detect any problems with either your electronic control unit or fuel injection system if they were broken in some way Broken Oxygen Sensor. So, for all this, (cold individual, dirty place)I was going to originally give him a 2 star. . Several smogs occur here as the mountains cause temperature inversions which trap dirty, polluted air and dont let it disperse. Let it sit for a few hours or overnight. Remove the air cleaner housing to get to the ICV and hoses.