If you get an OX1 or other error code on the EZ Lynk when trying to calibrate your fuel tank, this is going to be an error code that EZ Lynk's technical support will need to address. Their number is (877) 207-5530 or you can reach them via email at support@ezlynk.com. If you don't get an immediate response, please reach back out to us. - Thank you S&B