Please help regarding my automatic transmission. The problem arises when i notice it was emitting black smoke then i have my nozzle tip clean, after cleaning, the smoke is gone but engine lost power. So the mechanic suggest i calibrate the injection pump,the defect is a damage piston with four dent at the end. After calibrating, it emits black smoke and the mechanics put a gi sheet on the gasket to bypass the egr. When test driving, i notice it lacks power and the transmission hardly shift, it shift at 2000rpm, after that it hardly accelerate. I went back to the mechanics , he suspect its the transmission,maybe something is wrong with the module or sensor. I got a second opinion from a transmission specialist and he diagnose maybe the injection pump is delayed. I am confused now whether who to listen. Please help