AEM Fuel Pressure Gauge An important parameter to keep your eye on when tuning is fuel pressure. When on the dyno, most tuners will tap into your fuel system to monitor fuel pressure to make sure they are getting the most out of your set up. Once off the dyno, how will you know when there's a problem? Can you really hear the knock over the sound of your engine if you run a little lean? Is a crushed ringland worth betting on? Ever had a fuel pump "go soft" on you? Maybe your fuel filter is old, or you got a "dirty" tank of gas. Maybe you have an adjustable fuel pressure regulator and think it got tinkered with. Yea, we've been there too. Let the AEM Fuel Pressure Gauge work in conjunction with your AEM Air Fuel (UEGO) Gauge to let you know what's really going on under your hood. A must have for those with a highly tuned car on the street or the track.