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?
Truck will not test secondary system monitor reads not ready. on 2001 Chevrolet Silverado 1500
by dr detroit in Dixon, CA on October 24, 2013