I drive a 2003 Honda Accord v6 coupe automatic transmission. I've had the car for a year now and sometimes when I'm driving my emissions light comes on and when I stop at a stoplight my car will make a thump noise and when I push the gas pedal my car will very slowly accelerate. Even if I push the pedal all the way down I can only get up to about 20-25mph very slowly. Once I get above 25-30mph if I let off my gas and push it again I will start going normal speed but in a lower gear than normal because my rpm will be about 500-1000 over what it normally is. When this happened today my TCS light came on too. Someone told me it might be water in my gas tank but this has happened 3 or 4 times since I've owned it. I took it to autozone but their computer said it had to do with something electrical but the problem will usually go away if I turn the car off and start it again. The previous owner was my older sister so I know that it wasn't neglected maintenance-wise but I have no idea what could be causing this. The only thing that might need servicing soon is the serpentine belt but I'm pretty sure that's not it. Any help would be much appreciated.