I have a 99 C6500 with a 454ci With and automatic trans. It lopes or hunts at an idle, with the ses light on. Code is O2 bank 1 sensor 1 always lean. The short term fuels on the scanner are bank 1 48.5 bank 2 -2.31. Has 45 to 50 psi for fuel pressure. If you r... Login to read more.