Thats because you have a engine mangement problem. You need a computer to download the memory on the ECU. It could just be a sensor or it could be something more serious. The loss of power is natural when the E.M. light comes on, the engine runs at what is called "A Loss". If you live close then I can do that for you but if you don't, then you will have to take it to a garage. When you do this and find out what it is then I will help you to replace whatever is wrong rather than taking it to a garage. E-mail me at: trit666@hotmail.com.
Kind Regards.
Tristan Hanwell
May 2006