Audi Repair: 02 sensor, sensors, good luck

Question
Is there any difference in either of the front 02 sensors (left vs right)? same for rear?  Also, I see them sold with and w/o connectors.. (difference of ~$100 bucks) I need 2 and would like to save a few hundred dollars.. how bad would it be to use the old connectors and splice them to the new sensors?
thanks,

Answer
hello
I think front are the same( but not sure) Rear sensor are difrent (left and right). Most aftermarket sensor will come with out connector. It's up to you what you want on your car. I will try save some money.-- easy--
good luck                          pltech