Reduced Engine Power and 4 codes on a 2018 Chevy Malibu.

This Chevy Malibu has the 1.5 Turbo engine. It has the following 4 codes P0121 Throttle position sensor performance This code was repaired by changing the throttle body as in the video. Check engine light came back after I posted the video. The codes were P0236 Turbocharger boost sensor performance P0299 Engine underboost P1101 Intake air flow system performance I asked the owner to remove the front bumper for me in order to diagnose the these codes which could be caused by the turbocharger boost sensor that is located behind the front bumper. He was suppose to do so and call me. They did not want to remove the bumper because it is an aftermarket one and it will never sit correctly after taking it off. I told him I wasn't gonna work on it until he does so. He used my repair direction and hired a parts changer to replace the sensor for him without any diagnosis on the circuit. They were lucky! These codes also apply to other GM 1.5 Turbo engines like the 2017 Chevy Equinox and so on. The video also includes a how to replace a throttle body on 1.5L turbo charged Chevy engine. after doing so you need to do "Intake system learned values reset" and "Throttle body idle air flow compensation reset"