Oxygen Sensors On A 99/ Lx470

[LEX470LX]

Can anyone help me out with this I got a ECU code of P0135 If I remembered right it is an O/2 sensor bank 1 sensor 1 is the left side front ? ANYONE KNOW IF THIS IS CORRECT ?

Also how many O / 2 sensors are there on the 1999 LX 470 4 2 rear & 2 front ? are the 2 fronts same part #er's ? are the rear the same part # er's ?

anyone now the code's from the ECU ? If so can you list them .I will gratefully appreciate any and all help with my Questions

Also I found a web site with great price's for parts for all makes models I got Bosch Premium Oxygen Senor's for the LX 470 $77 each after I found a 10% off any order over $100 ( did a search of the web site & coupons added at the end and I save $18 on my order of 2 O2 sensors site is DRIVEWIRE.COM

THANKS FOR THE HELP !