Hi Dennie, I'm happy to assist you. The location of the MAP sensor for your 1991 Chevrolet Corvette with a 5.7 liter engine is on the side of the intake plenum. We suggest that you refer to a vehicle repair manual for more details. This part is incompatible with the chosen vehicle. Click this link to order the MAP sensor that fits your car while it's on sale: https://www.carparts.com/search?q=MAP_Sensor&vehicle[year]=1991&vehicle[make]=Chevrolet&vehicle[model]=Corvette&vehicle[submodel]=Base&vehicle[cylinders]=8&vehicle[liter]=5%2E7&filters[universal]=false&can=CPAP3648 I hope this helps. Enjoy shopping at Carparts.com!

Hi Brandon, In fuel-injected automotive engines, a manifold absolute pressure (MAP) sensor is used to continuously monitor the amount of air flowing into the engine, so the computer can calculate air density, adjust the amount of fuel to spray into the combustion chamber and adjust the ignition timing. But still, it is best to consult with your trusted local automotive repair shop/dealership for an accurate diagnostic on your vehicle.

Won't start, or stalls and misfires also reduced fuel economy

Hi Candi, I'm glad to help you out. As per automotive guide, below are some signs of a failing MAP sensor: Poor fuel economy, lack of power, rough idling, hard starting, and many more. We highly recommend that a certified mechanic diagnose the vehicle to pinpoint what part needs replacement. Should you need to order this part, click the link below: https://www.carparts.com/map-sensor/ac-delco/ac2134434?can=CPAP3648 I hope this helps. Happy shopping.

Hi Brandon, It continuously monitors the amount of air flowing into the engine so that the engine control module can calculate air density, adjust the amount of fuel to spray into the combustion chamber, and adjust the ignition timing.