dieselz

The P0741 code and high transmission temperature are likely due to a torque converter clutch (TCC) issue, not the throttle body relearn. Check your transmission fluid level and condition first, as low or old fluid can cause overheating and gear slipping. The TCC solenoid or torque converter may need attention. The throttle body relearn is probably unrelated to these transmission problems.

To address the persistent P0430 code on your 2014 Silverado, consider checking for exhaust restrictions beyond the catalytic converter, inspecting O2 sensor wiring for damage, and possibly updating/reprogramming the ECU. Also, revisit the possibility of a small exhaust manifold or gasket leak on the passenger side. Fixing the low oil pressure sensor (P0521) may not directly resolve the P0430 code, but it's worth addressing to rule out any related issues.