Spark Plug for 4AGE BT 20v engine is IK20.
For further information, u may refer this website
http://www.globaldenso.com/en/products/aftermarket/plug/basic_knowledge/heatrange/index.html
i am at the middle of filling the Check list for Works P1 Flash... by http://www.workevo.com .. here is something i donno... i hope sifu here can help me :D