Chasing down lack of power and low mileage
4x4 model, 125k miles, 4" turbo back, SuperChips at Hi-Perf.
I'm trying to locate a low power issue and a significant decrease in fuel mileage over the past year (11 city regardless if i stomp on it or drive like a grandma). The truck seems like it needs a significant amount of pedal to get moving and the engine cackle is much louder than seems appropriate for the acceleration. I have an AE for testing suggestions.
Front brakes do not appear as if they are hanging. Unsure on rear.
Contribution fails on number 8 due to the CPS, AE shows velocity change of 6% on 8 and 3% on 3. Very common with the CPS issues. All buzz tests and standard tests show normal results. Max boost is easily 27psi, where 50% accelerator usually hits between 10 and 14 psi.
AE graph of ICP, DC%, RPM and Boost attached. Total of 3 runs. Any ideas of what to check next?