Here is a follow up to my post on the Cat C9S Check Engine light and related issues. To review, the yellow check engine light came on about 500 miles into a trip 920 miles south to Indio, CA. The light would not reset, indicating an active issue. Then, about 300 miles out at an elevation of 7,300' the engine lost power 3 times in about 15 seconds but regained full power and ran fine for the balance of the trip down. (At no time did a red check engine light illuminate.) I had a diesel mechanic, not from Cat, come to the RV park and run the codes. The first was an inappropriate response from the #2 fuel injector. It would not reset and the light remains on. He found a second code that would have given a yellow check engine light had it not already been illuminated from the first issue. The second code was an inappropriate response from the turbo actuator. ( the power loss issue at the high elevation) That situation resolved itself and the light went away. The closest Cat facility is about 75 miles away in Riverside, CA. That was in mid October of this year. So now we are back in Bend, OR having driven our tow home for the holidays. This morning I visited with the Cat dealership in Redmond, OR where the coach is routinely serviced. They were most helpful and told me the specific code I gave them was related to the fuel injector monitoring system and would have no bearing on the operation of the engine, which runs fine. The actuator code was related to the geometry of the tubo blades and may or may not be a continuing problem. But in any case I was given a green light to drive the coach back to Bend in the Spring and have it checked out by them at that time. That's what I know at this time. Thank you all and particularly Dave for the great input. And to all, a very Merry Christmas and safe travels in 2019.
Robin G