OBD-II DTC: P0171 System Too Lean (Bank 1) read that and do as it says before buying anything. clean the maf, check for vac leaks with carb cleaner.

if your talking about the 2 bolts that hold the egr to the pedestal on the tubes, that can cause a vac leak. fix that up. that maybe causing both codes.

the egr code. was it a p0404? i had the same code come up low voltage. the light went off on its own, and then i still changed it. all good so far.