Do I need to do a custom OS to run open loop SD mode? I am helping a friend tune a LQ4 with a cam and injectors in a off road jeep and see no reason to try and tune in a MAF and the exhaust is about 2' past the header straight pipe, its not derivable on the street so I want to be able to get him something close quickly and add to the tune as I can get some logs when he is off road, we do have a WBO2.