I have P0171 DTC Bank 1 system to lean & P0174 system to lean bank 2

A common misdiagnosis is oxygen sensors. Look at the simplest things first when these two codes come up. Check your PCV valve and all lines from it for cracks, check vacuum lines, just listen for a hiss anywhere under the hood that isn't normal. If nothing is found there then check your MAF sensor. A leaking vacuum line or gasket in the intake side is where I would place my money.