take it from a person who is turboing a obd2 car it is a pian inthe *** to do there is some much converting to do like ecu fuel injectors and o2 sensor and emision is a pian 2 in order to pass u have to convert everything back to obd2(stock) in order to go down and pass if i had a choice to start over obd1 is the way to go but good luck on wat ever u do i like the ek hatches better so i opted to go obd2 and do wat u like and have fun