Been having p0171 and p0300 on the vehicle. scanned it and observed that the bank 1 always go into open loop fault intermittently when idle and there is no reading on the SHTFT and LTFT on the bank 1. so i changed the o2 in the up stream of bank 1 and no more open loop fault intermittently but still have the p0300 and p0171.  Another thing i noted after changing the o2 on bank1 and compared the readings of the SHTFT  and LTFT of bank 1 to bank 2. on idle bank 1 STFT AND LTFT was approxmately -1.0 and 0.0 respectively and on bank 2  SHTFT AND LTFT i was having approx 14.0 and 10.0 respectively.  When i rev it to 2500rpm  bank1(SHTFT, LTFT) is approx( -5.0, 0.0) while bank2(SHTFT, LTFT) approx( 8.0, 0.0. ) so the car still has p0300 and p0171.