The manifold absolute pressure (MAP) sensor is used on fuel-injected engines, such as the 3.4-liter V6, to send manifold pressure information to the computer. The computer uses this signal to determine air density and the air mass flow rate from the engine. With this information, the computer can then determine the proper air-fuel mixture for optimum combustion which, in turn, gives the best gas mileage. To make the best use of the information from the MAP sensor, the computer must also know how fast the engine is turning (RPM) and what the outside air temperature is---the computer gets this information from additional sensors on the Chevy.
Open the hood of your 3.4-liter V-6.
Locate a small, rectangular-shaped sensor with a vacuum line attached to it near the rear of the engine or on the firewall, depending on the year and make Chevy vehicle that the 3.4-liter V6 engine is in.
Verify that the sensor's plug has three wires in the wiring harness plug. The plug on the wiring harness is "male" and has three prongs that insert into the "female" plug connector on the MAP sensor.
