ok, so have my accident back in January my car has not been the same at all.

The A/C has been very inconsistent. I don't know if it is just the extremely hot weather in Florida, but I have noticed that when I am idle the car just blows hot air and once I accelerate it blows cold air, but I usually notice this when it is hot outside. Also when this happens especially in stop and go traffic, once I get into thrid gear the car begins to buck even though I am constant at gas at a steady 25-30 mph.

So fat forward to today, I was driving with A/C and hear what sounds liek knocking. I cant say it was engine knocking since I have no clue waht that soudns like, but it pretty much sounded liek someone knocking on the door coming form the fron tof the car. I cam to idle and it still happens. I turn off A/C and it stops. Then I try to turn A/C again and it wont turn on (about the third time this has happened). The knocking never came back. After about 5 minutes of driving the A/C works again.

Any clue as to what may be going on?

Something to note and something I never checked, not sure if this may be contributing to the problem, apparently they had to rewire some of the electrical components. I had cobb AP tuner installed initially with turboback exhaust. I never checked to see if cobb works again and or checked if they possibly changed my ecu as well. Could this be causing any problems as well?