Oxygen Sensor

[Cree]

Hey guys
I bought a new wagon; 2007 my08 2.5i heritage to be exact.
I purchased the car knowing the O2 sensor was screwed (no cruise control, cruise and engine light on, rough idle and start) and I've been eager to get it replaced.

I'm after some knowledge of what part I should be getting exactly. My local mechanic told me I'd be in need of a post cat sensor, and this Is the best I've found so far: http://o2sensors.com.au/product/4553/5589

Can anyone confirm this will work fine or suggest anything cheaper and/or more suited?
Thanks a lot in advance, love you all

[HardwareBoB]

Code P0420 seems to be a failure of the post cat O2, but what it means is that there is a mismatch between the front O2 sensor and the rear O2 sensor. It is almost certainly the FRONT O2 sensor you need to replace, not the rear.

[DownUnder]

Get it from partsouq.com cheapest price by far!

[Cree]

Code P0420 seems to be a failure of the post cat O2, but what it means is that there is a mismatch between the front O2 sensor and the rear O2 sensor. It is almost certainly the FRONT O2 sensor you need to replace, not the rear.

Took it back to my mechanic and asked him to check. You were spot on.
He cleared the codes and said to wait see if the issues are reoccurring. If so ill be replacing the precat instead of the post.