Indmar MAP Sensor - Chevrolet 5.7/6.0/8.1 Manifold PressureRestore smooth performance and reliable engine management with this Indmar MAP (Manifold Absolute Pressure) sensor for select Chevrolet based Indmar marine engines. The MAP sensor measures intake manifold pressure and sends the signal to the ECM PCM to help calculate correct fuel and ignition timing. A failing MAP sensor can cause hard starting, rough idle, hesitation, poor acceleration, rich lean running, and reduced fuel economymaking this a key