Where is the MAP sensor located and how hard is it to change on a 1999 2500 Cummins???

 

On the drivers side of the engine....Its towards the firewall side of the fuel filter. I think you just unplug it and then its a fairly good size metric socket to take it off.
TNutcher

 

Fuel System Components - 24-valve Cummins Turbo Diesel engine.
1. Fuel Transfer (Lift) Pump
2. Fuel Return Line (to Fuel Tank)
3. Fuel Supply Line (Low Pressure, to Engine)
4. Fuel Heater
5. Water-in-Fuel (WIF) Sensor
6. Fuel FilterlWater Separator
7. IA T Sensor
8. Map (Boost) Sensor
9. Fuel Drain Manifold
10. CKP Sensor
11. CMP Sensor
12. Overflow Valve
13. Drain Valve
14. Fuel Pressure Test Potts
15. ECM
16. ECT Sensor
17. Fuel Injection Pump
18. Throttle Lever Bell Crank and Apps
19, High-Pressure Fuel Lines
20. Fuel Injectors
21. Fuel Heater Temperature Sensor (Thermostat)
22. Oil Pressure Sensor
23. Fuel Injector Connector
24. Drain Tube
25. Intake Manifold Air Heater/Elements

 

Look at the picture in the previos post to find the MAP sensor. Unplug the electrical connector on the MAP sensor. Take a 32mm deep socket and remove the sensor. You might want to try cleaning the old one before you replace it. You should use electrical contact cleaner, but carb cleaner works too.