Report: Check Engine Light With Code P0138, P0140, P0158, and/or P0160
Infiniti QX4 Problem
The Check Engine Light may illuminate with code P0138, P0140, P0158, and/or P0160 stored. Our technicians recommend replacing the rear oxygen sensor, and reprogramming the vehicle's powertrain control module (PCM) with upgraded software to correct this concern.
Visitor, 1999 Infiniti QX4, 148,000 mi
Check engine light stays on. Had it checked at local repair shop and it's the o2 sensor. Owner/Mechanic said it's not a big deal from the point of view of driving the car but will have to deal with it in order to pass next inspection. He said it's expensive, around $600.