OTC 7215 Exhaust Back Pressure Gauge
Now there's a fast, easy way to read exhaust back pressure to help determine the extent of restriction.  Its large, easy-to-read gauge clearly shows pressure from 0-8 PSI.  The tip is specially designed, which provides more accurate pressure reading while stainless steel braided tube, withstands high-heat engine conditions. For use on GM, Ford, Chrysler and imported vehicles.