Map Sensor

The HOLLEY Map Sensor (model 538-13) is a 2 bar manifold absolute pressure sensor engineered for naturally aspirated and boosted fuel-injected engines running up to 15 psi of boost pressure. This critical engine management component measures intake manifold pressure in real-time, allowing your vehicle's ECU to calculate precise fuel delivery and ignition timing. Built to Bosch specifications and standards, this sensor is essential for carbureted-to-fuel-injection conversions, turbo and supercharger installations, and any performance application requiring accurate air-density compensation.

The Map Sensor operates using a pressure-diaphragm design that converts manifold vacuum and positive boost into a proportional analog voltage signal. At idle and cruise, intake manifold pressure is lower than atmospheric (vacuum), and the sensor output reflects this negative pressure; under acceleration or boost, pressure rises and the signal increases accordingly. This 2 bar range provides optimal resolution for street and mild-to-moderate forced induction applications, translating directly into faster, more responsive fuel mapping and improved engine efficiency. The compact, lightweight design (0.2 lbs, 3.55 x 2.5 x 3.7 inches) allows flexible mounting near or on the intake manifold without adding bulk or weight penalty.

Carburetor-to-EFI retrofit builders, turbo enthusiasts, and engine control system integrators will find this HOLLEY Map Sensor indispensable for dialing in fuel tables and air-fuel ratio stability across the RPM band. The Bosch-style electrical connector ensures compatibility with most aftermarket ECU platforms and factory-style standalone engine management systems. Installation is straightforward: mount the sensor to a boss on the intake manifold or adapter plate, route the vacuum reference line to the intake manifold, and connect the three-wire harness to your engine control unit. This single unit is sold as a complete sensor assembly.