Found this website regarding the O2 Simulator which should be able to fix the CEL issue. My car CEL always ON after remove the catalytic convertor.
http://www.voodooboost.com/performan.../O2_Simulator/
Wondering anyone carrying it in Malaysia or shall we get a group purchase?
http://www.voodooboost.com/performan.../O2_Simulator/
Wondering anyone carrying it in Malaysia or shall we get a group purchase?