I recently had my exhaust welded closed right after the headers to quite it down and restore my back pressure and now my computer is saying the system is to lean on both P0171 bank 1 and P0174 bank 2. I also have a pending code of P0401 Exhaust Gas Recirculation Flow Insufficient Detected. I noticed the a line was broken near my battery and didn't know where it goes and if it's caused my problem.

 

Found out what the hose was for and fixed it but still have the code for bank 1 and bank 2 being lean.