DENSO Part # 2344205 Upstream DENSO Part # 2344061 Downstream 101.35 Shipped ULTRAPOWER Part # 2344205 Upstream ULTRAPOWER Part # 2344061 Downstream 71.14 Shipped So being that they are the same part number, can I assume the same sources makes them for both companies? They both have a year defective warranty. I read somewhere that getting OEM equipment (Denso for the corolla) is more important because with oxygen sensor, even a slight different in voltage can cause differences in MPG and other issues? I have used Denso oxygen sensor on my celica gt with great success but this order isn't for me but rather my sister and she would want to save money unless you guys believe that saving the $30 dollars is not worth it. Thank You.