P0131 and P0171 codes..trying to fix and clear them out.

Question

These codes keep popping up. I have changed both O2 sensors.
Replaced the Fuel Filter with a new one.

Still have this code problem, and getting 6mpg instead of 22mpg.
Car has a rough shift with the automatic transmission.

Answer 1

P0171 Fuel trim lean Bank 1

P0131 H02S voltage shorted to ground, Bank 1 Sensor 1

At the 02 sensor Bank 1 Sensor which is the first 02 sensor, open its harness and look for any shorts wires this year type of vehicle had wire wrap in convolution  for the front 02 sensor which tends to short out, when this does the ASD as well as the fuel pump is affected.