I went to Southwestern at 11 am wanting my inspection done. Unfortunetely, my "Service Engine Soon" light was on. I was charged $45 to check what was wrong. Two codes appeared, one for the Coolant Temperature Sensor and one that showed "No Definition Found". I was told that he could replace the sensor for $35 if I bought the part from O'Reilly. I bought the part and he replaced it. I was then told that I had to drive the car for 80-90 miles because there were 5 codes that were "incomplete". I drove 30 miles and the "Service Engine Soon" light came back on. I went back to Southwestern at 1pm and he checked the codes. The "No Definition Found" code appeared. He opened and closed the gas tank and cleared the codes. He then told me to drive around again to see if the light came back on. It did after 20 miles. I came back at 3pm and he told me to come back on Monday because they were about to close.

Things to note:
AutoZone checks the codes for free (not $45 like Southwestern). AutoZone explains what the codes mean, even the one that showed "No Definition Found" at Southwestern (it was an Intake Air Temperature Sensor). AutoZone also told me that Southwestern should have disconnected the battery to reset the computer, they didn't.

Conclusion:
Southwestern did not seem knowledgeable about the codes. They were able to replace the Coolant Sensor but they didn't disconnect the battery to reset the computer. They also couldn't tell me about the Intake Air Temperature sensor. I will be taking my business elsewhere.