Thanks for the response. I checked the OBD temps today on my commute home from work. I checked the local temp on my phone first and it was 89 degrees F outside. On the hidden OBD 7.1 (ambient temp), I got a reading of 275 with the car off. This varied up to 420 on my 30 minute drive home. I am assuming this is supposed to be in degrees C?? Can somebody confirm that I definitely have a bad ambient temp sensor in the driver's side wheel well?? Sure looks like it, unless I am interpreting the readings wrong. Hopefully this is what is causing my AC to not work.
On the 7.0 coolant temp readings, I had a reading of 33C when first starting my car (or 91F which seems right as it was about 90 outside). It climbed to about 88C (190F) after 10 minutes sitting in stop and go traffic. It then dropped down to 81C (178F) when I finally got up to about 50mph on the freeway. Seems like I need to replace the thermostat, correct?