I have a 2006 Silverado 2500HD LQ4 6.0L. I found this problem when trouble shooting my lean condition at WOT which was the fuel filter so I had to replace the fuel pump assembly.
The system will still go into OL when it is in DFCO or during a cold start. But I can not get it to go into OL at WOT so it is not doing the Power Enrichment either. Here are some of the Specs from the data log which from what I gather they all point to say it should go into OL
@WOT 4473rpm
Manifold Absolute Pressure 96.0KPA
Mass Air Flow 233.95g/sec
Throttle Position 100%
Manifold Vacuum 0.39psi
Intake Air Temp 64deg
Coolant Temp 199deg
Calculated Load 91%
Fuel Trim Cell 15
Delivered Engine Torque 349ftlb
Dynamic Cylinder Air 0.79g/cyl
Fuel System Status CL - Normal
Air Fuel Ratio Commanded 14.68
The truck is stock and the tune on my LQ9 Jeep YJ goes in OL just fine so I compared the Tunes and do not find differences in any place that would cause this.
Any ideas? Thanks