My 2.9 CRDI 2006 Terracan with auto transmission does not perform well, hope some of you have a solution. Works fairly well in Ecuador sea-level and mid elevations. 1-100Km/hr (62MPH) takes 23 seconds. Very sluggish in higher elevations, i.e. at 8,000 level (especially at startup), will not even move with full throttle, then picks up speed slowly. Going over the mountains, in 2nd RPM will sometimes drop to 2,000 RPM or below and I have to shift to Low, but will not rev above about 3,700 RPM. First time ever on recent trip over mountain, felt surge off power in low (like turbo finally working?) at 3,700 and quickly ran up to 4,400. Did that about three times, then did not. I've changed the MAF. No Codes show.