Truck will not test secondary system monitor reads not ready.
What is your question?
With scanner can turn on and off air pump. Found both check valves plugged replaced but still will not run monitor can watch pid data both o2 sensors drop. replaced both front o2 sensors just in case they were lazy. What else is need to run monitor?
RepairPal Certified shops can diagnose and repair your 2001 Chevrolet Silverado 1500. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.