2003 Saturn L200

I have a 2003 saturn L200 with about 72,000 miles on it. About a week ago my car service light would come on and then my gas and temp gauges would both drop to zero for a second or two then they would resume normal levels again. A couple of days later my security light would come on then the service light would come on and gauges would drop also. So I took my car to auto zone to have them do a computer and alternator check on it. The computer check said nothing was wrong, the alternator was pulling 225 amps though. So I replaced the alternator today and the problems continued, but now after driving for about 10 - 15 minutes the fan will kick on and stay on. Also when the car shifts theres a big jerk and pop and this happens between every gear. I took the car back to auto zone ran the computer check again it kick out code P0113 which says the input from the intake air temp sensor is higher than expected for thge current engine operating conditions. Was just wondering if you had and idea of what it could be, because im stumped. Thanks