I have a 2000 4x4 with 149,000 miles on it. I have had very little problems with this truck. I replace the LP a few months back and now my engine light comes on, the tach works intermittently and I have power loss when the tach doesn't work. After reading through the threads here I believe the problem to be the CMP Sensor. Am I correct?

 

Check out this link and see if it helps: http://www.dodge-diesel.org/articles/cps/ckp.htm

 

Don't rule out the IAT its purpose is to measure the Intake Air Temperature, control mixtures etc is it's main purpose. Should be part of your intermittent service schedule. These are normally fouled out every 150 thousand miles but are often caked with oil. One last thing..before you change anything check for leaks around the wastegate on the turbo and the intercooler system. If any of these were issues your ECM would signal the engine to cut power. Hope this helps. The CMP Sensor or a combination of all three is some times indicated as all will cause the ECM to cut power. In most cases if your tach is not acting erractically it will be the IAT which is located behind the distributor ,right side of the engine as you look from the end of your truck.