i believe that his 13.2 at idle may have something to do with the wideband positioning and getting a false reading. at idle these cars run on closed loop and the ecu will always compensate to keep the car stoich at cruise and idle. of course if the car has aftermarket injectors then that is a different story sometimes depending on how large the injectors are the ecu may not compensate or if it has been tuned to stay on open loop at all times.