Ok my hawk has been running great lately, until earlier today, now this may be a coincidence, but when i was out in the rain, the car started idling rough, almost like it has a mild cam in it. When i put it in park, or neutral its better, but when the car is in drive, and im pressing the brake when im coming to a stop, it shakes pretty bad, any ideas?

 

Does it still have EGR? If so it may be sticking. Try disconnecting the vac line and plug it and take it for a ride. Also check the valve for looseness or leaking. Could be the IAC or the FPR may have a hole in the diaphragm. check the IAC counts if you have a scanner should be around 20 to 40.