Sorry...I'm a little late to this party since I don't come into the V8 section much. I realize that your problem has been solved but I wanted to leave some info here for others that might need to get their monitors readied asap to pass an inspection. I live in Texas too and I have some experience in this area...the process can be done in a lot less than the 700 miles you had to drive. A complete driving cycle done step by step will perform diagnostics on all monitored systems and can usually be completed in less than fifteen minutes.
Performing a GM OBD-II Driving cycle:
Cold Start In order to be classified as a cold start the engine coolant temperature must be below 122 degrees F (50 C) and within 11 degrees F (6 C) of the ambient air temperature at startup. Do not leave the key on prior to the cold start or the heated oxygen sensor diagnostic may not run.
Idle The engine must be run for two and a half minutes with the air conditioner on and rear defroster on. The more electrical load you can apply the better. This will test the O2 heater, Passive Air, Purge "No Flow", Misfire and if closed loop is achieved, Fuel Trim.
Accelerate Turn off the air conditioner and all the other loads and apply half throttle until 55mph (88km/hr) is reached. During this time the Misfire, Fuel Trim, and Purge Flow diagnostics will be performed.
Hold Steady Speed Hold a steady speed of 55mph (88km/hr) for 3 minutes. During this time the O2 response, air Intrusive, EGR, Purge, Misfire, and Fuel Trim diagnostics will be performed.
Decelerate Let off the accelerator pedal. Do not shift, touch the brake or clutch. It is important to let the vehicle coast along gradually slowing down to 20 mph (32km/hr). During this time the EGR, Purge and Fuel Trim diagnostics will be performed.
Accelerate Accelerate at 3/4 throttle until 55-60mph (88-96 km/hr). This will perform the same diagnostics as in step 3.
Hold Steady Speed Hold a steady speed of 55mph (88km/hr) for five minutes. During this time, in addition to the diagnostics performed in step 4, the catalyst monitor diagnostics will be performed. If the catalyst is marginal or the battery has been disconnected, it may take 5 complete driving cycles to determine the state of the catalyst.
Decelerate This will perform the same diagnostics as in step 5. Again, don't press the clutch or brakes or shift gears.
I did find the decelerate steps to be the most difficult to perform under normal driving conditions so I waited to do all this at night on the highway...just put my flashers on and let it coast down under 20 mph each time.