My 99 Explorer 4.0 ohv sets those three codes, please help

P0171 is a systems lean bank 1, p0174 is system lean bank 4. I had this. I cleared it Friday morning. Engine blew up friday night. I have no idea what went wrong. I am going to diagnose Sunday.

I cleaned the MAF, light goes out comes back on. Disconnect the battery and hold the terminals together for a minute, light goes out comes back on. Long term fuel trim goes wacky and then good. Maybe its the PCM

Could be or sensors.......Monitor the pids for upper and lower o2's when engine warm or operating temp

Check for loose intake manifold bolts and leaks in the intake system between the MAF and the throttle body.

REdo the scan. p1000 i think is a messup with the vehicle run time