What Fixed the 2011 Silverado Reduced Engine Power with codes P0220, P0222, P1516 and P2135.

After a throttle body, ECM computer, what ended up fixing this 2011 Silverado with reduced power. Was it the grounds? ACDelco GM Genuine Parts 21486 Negative Battery Cable https://amzn.to/3KROmVm Fluke 107 AC/DC Current Handheld Digital Multimeter by Fluke, Gray https://amzn.to/3OPu6of Fluke AC220 SureGrip Alligator Clips https://amzn.to/45LnDSq The links I provide are Affiliate links that I earn a small commission from but don't cost you anymore. Thank you for your support. 737mechanic Amazon Store Front https://www.amazon.com/shop/737mechan...