The minder only detects restriction of air running thru the filter (s). Mine is connected to the air box cover by a rubber grommet that was supplied with the filter a very tight fit. A clean filter even at WOT will not show any restriction on the gauge. You can test the gauge by just sucking on the inlet side of the minder. It takes very little suction to cause the plunger to move in the minder. My Ford 250 diesel has one installed by the factory except it has a electric sensor that shows on my dash, the same deal could be fitted on a sxs easily. Go to the filter minder web site and check out what they have for options.