The P0108 code refers to a problem with the manifold absolute pressure (MAP) sensor, while the P1297 code indicates an issue with the MAP sensor vacuum. Since you mentioned that the MAP sensor has been changed, it's possible that there could be a wiring issue or a problem with the sensor's connection. I would recommend double-checking all the wiring connections related to the MAP sensor and ensuring they are secure and in good condition. You'd be surprised how often situations like this end up being a break in the wiring harness somewhere.
Additionally, since you mentioned that the transfer case and transmission have been replaced in the past, it may be worth inspecting the wiring and connections related to these components as well. Sometimes, the wiring harness can become damaged or corroded during the replacement process, leading to electrical issues and fault codes.
If the wiring checks out, it may be necessary to perform a more thorough diagnostic procedure using a scan tool that can read live data from the engine control module (ECM). This will allow you to monitor sensor readings such as the MAP sensor's voltage, as well as other relevant parameters, to help pinpoint the source of the problem.
Get ready to get to work! If it's a wiring issue they can often times be tough to track down.
