I just bought O2 sensors (bosch) from advance auto for about the same price that you can get them from rockauto shipped. Advance Auto has a rebate for $10 ea, max 4 for Bosch and NTN O2 sensors.

Downtreams were $73 for both after rebate.
Upstreams were $39 each after rebate.
$112 for all 4 Bosch O2 sensors isn't too bad

I placed 3 separate orders.

1 order for each upstream with a filler because the coupon code needed an order of $75 or more and the O2 sensor was $74.99. Picked up each order at a local AAP.
1 order for both downstreams, used a 35% off coupon. had it sjipped for free because the order was over $75.

The rebates are easy to submit online. Nothing to mail in.

 

Great deal!! I'm in need of all 4 sensors so I'll have to try and figure this deal out. Thanks for the heads up

 

Here is a site that lists AAP coupon codes: http://www.retailmenot.com/view/advanceautoparts.com

WD25 - $50 Off Order Over $125 + FREE Shipping On Orders Over $75
TRT30 - 30% off
TRT41 - $40 Off $100+ On Regular Priced Items + Free Shipping
TRT37 - $30 Off $75 + Free Shipping

I would place 1 order for both the downstream using WD25.
$63.99 ea x 2 = $127.98 - $50 = $77.98 + tax. (-$20 rebate) = $57.98

Place an order for a upstream using TRT37 and a filler to get you over $75.
$75-30= $45 + tax (-$10 rebate) = $35