Do you mean the Mill light (The little Engine light that looks like a helicopter), and is it Orange?
If it is, I agree with Pinky, there is no way that your mods have caused it to come on, i recon you have deeper problems.

I had this on my first

, it turned out to be a faulty Alternater.
Phone the AA, and when they come out ask them to check the voltage output.
Or, have you put some of that cheap Supermarket petrol in that makes the Hego sensors drunk

, thereby, maybe throwing an emissions fault up.

Good luck and keep us informed.
