I don't have a mass air flow sensor I have an air temp. sensor and I just drilled a 5/8 hole in the pvc as close to the original location as I could get. Inserted a 1/2" rubber grommet in the hole and secured it with a little glue and then just pushed the sensor into the grommet. It fits pretty tight but you don't have to worry about it falling out that way.I also have a question. If I was to do away with the filter box and install a cone filter could I just unhook the vacuum line going into the top of my air cleaner box and put a filter right on the end of the vacuum line? I'm thinking seriously about doing this if that is all I need to do. Here is a pic of the cai I did before I switched the ss pipe out for pvc but it shows the vacuum line in the air box I'm talking about.