The MAP (Manifold Absolute Pressure) Sensor measures Vacuum Pressure for the PCM which constantly changes depending upon engine load. Typically used in EFI Speed Density, the MAP provides instananeous Manifold Pressure data which is cross-referenced with engine RPM and air temperature data to determine the engine's air mass flow rate. This information is referenced to tables which allow the PCM to determine air/fuel ratio, ignition timing, transmission line pressure and shift scheduling for higher altitude operation.How or what all is necessary to install a map/Baro sensor in my 94 so that the tune will be happy and the cel will go off?
To build on what Steve83 is saying, you probably have a different EEC than what came from the factory - or replaced the transmission. To confirm, look at your EEC Catch Code and see if there is a wire on EEC Pin #45.
See this link: MAP or BAP? Which Sensor is it?
Here is what you have...
All 1987-1995 Bronco/Truck/Van Speed Density PCM's have a MAP, with MAP Sensor Input on PCM Pin 45, VREF on Pin 26 and SIGRTN on Pin 46.
All 1994-1995 Bronco/Truck/Van MAF PCM's with E4OD Transmission do not have a MAP, except for the Bronco MAF 5.0L having the Mazda M5OD-R2.
All 1988-1993 Mustang MAF PCM's have a BAP.
All 1994-1995 Mustang MAF PCM's do not have a MAP or BAP.
Here is what you need...
When upgrading to a 1988-1993 Mustang MAF PCM, you must convert the MAP to BAP utilizing the same PCM pins.
When upgrading to a 1994-1995 Mustang MAF PCM, there is no MAP nor BAP. PCM Pin 45 is not used.
When upgrading to a 1995 F150 MAF PCM, there is no MAP nor BAP. PCM Pin 45 is not used.