Lexus IS Electrics, ECU, Warnings & Lights Problems

car will start, i can open with key from fob but alarm goes off. car will start.

The problem I have observed in my car is when I am accelarating the car it does not respond on some occasions it de-accelrate even though I am pressing down the accelarator and their is a flapping noise coming from the engin.

after i tow my caravan i keep getting warning beeps coming from the back of my car. this will go on for about a week , then the alarm system thats got a seperate battery back up goes off. how can i sort out this problem. help me im going nu...