Originally Posted by
rubrhammer
I'm still struggling with this 2002 LQ4 that won't go closed loop. I've used a different PCM, new O2 sensors and checked the wiring 3 times. The scan tool is showing activity for 4 O2 sensors when only 2 are installed. Sensor voltage ranges from .435v to .460v on all 4 lines on the scan tool. The activity is rapid changes as though it was in closed loop. It's very rapid. Scan tool then shows codes for no activity on them. Sensors are grounded to cylinder head and have 13.5v on the pink wire.
LTFT and STFT are flat line in live data on scan tool. LTFT and STFT are enabled in the calibration.
This is a Canadian VIN PCM for a 5.3 with 6.0 fuel tables imported. The harness was from the same vehicle. O2 sensor wires were not removed from PCM and were shortened one at a time. O2 sensors are for a Canadian 5.3.
I'm totally baffled. Any help would be greatly appreciated!!!!