How has your gas mileage been lately? I believe that if your temp sensor is gone the car will start fine and run open loop but will continue in open loop (running on the program in the prom) when the car is warm when it should actually be running closed loop (taking readings from sensors). This means that you will be running a rich condition when driving while warm hence worse gas mileage. It also means that the computer is running the cold start program when your engine is actually warm (too much fuel too little air) and would have problems starting. I dunno, just a thought good luck though.