Hi folks, my vehicle which is a 2012, with 125,000miles,. The engine is straight 6, with variable intake cam, and variable intake length. 5 speed Automatic. Recently the engine is showing lean conditions, short terms are above 15% and reach 21% on bank 2 for a few seconds, long terms are stable at 10%, as the ECM compensates. Fuel pressure at the pressure regulator is within spec, i have changed the fuel filter recently, but not my fuel pump.
Can this be fuel pump related, if the short terms return to less than 10% above 3000rpm, but only lean between 1500rpm to 2500rpm?
Update: 2012 nissan patrol y61, auto 5 speed....not sold in the US or canada. no dtcs are logged, and no Mil. engine is drinking a bit more fuel since May 2019. i have changed the MAF, O2 sensors on both banks at 80000miles. Engine was rebuilt due to warped head leaking oil, luckily no overheating, as oil was leaking out of the back of the block/head gap and not mixing with coolant. I have cleaned the MAF recently, and it runs better from stop, but the Lean running is still present from 1500-2500rpm. I have checked the fuel pump pressure, and it is within spec at idle, and when throttle is snapped.