Q: Replaced the oyxgen sensor, now the car won't start

Hello, thank you for writing in. If you used a universal oxygen sensor, you will want to make sure that it was wired correctly. If any wires touched or shorted out in the process, you may have also blown a fuse. It would be wise to check those fuses associated with the system. If you disconnected the battery during the process make sure its connections are clean, dry, and tight. You are working with some very basic systems, and it is likely something small causing your symptoms. Make sure your battery is fully charged, and attempt to jump start the vehicle if you have not already. Your OBD-II scanner is likely not making connection because the computer is not getting power. Your battery and the connection should be your main focus for now. For more help diagnosing the problem, contact our service department to schedule an appointment.