Engine light

I have been changing the exhaust on bike (RK 99), I just finished today, all I did was take v and h off, and put back the dual factory mufflers.

This took about a week and a half from start to finish, had to wait for pipes I bought to come in, and had to put off a few days to get parts from dealer.

The job went good and looks great, finally going to have the fiberglass bags instead of the leather throw overs. Forgot I did that too.

Now when I tried to start the bike to here how the exhasust sounded, the battery was dead. I jump started it from my car, and it started no problem.. Now the engine light is on, and stays on. I left it charge for a long while in the garage, hoping that this would turn the engine light off, well it did, so I decided to take it down the road to further along the batteries charge. Well not even 1000 ft and the light came back on, and I brought it back.

Is there something I did that caused this to happen, The only other thing that happened was the the oil was low, almost a quart.

I have since filled the oil and light still on, afraid to take it out for fear it will leave me sitting, I thought I would ask you guys before doing anything else, don't want to screw things up.

Bike has always run good before and never any problem, till I let it set for a few days to change exhaust.

Help is despartely needed