to all, i am facing abs problem in my stock standard satria gti '02 rides:

1) the abs light came on & when diagnosed it shown front brake sensor problem which I've it thoroughly cleaned & checked but not front only, even the rear were also cleaned & checked. But, the light still appeared!

2) another problem is, when the light is off (on & off actually) the pressing of the brake pedal wobble with kluk-kluk sound. But sometime no sound & smooth again.

Above problem have been tried to be rectified by not only 1 trusted mechanic but 2 workshop. So, what should i do now? Please advise.