Where to get O2 sensors?

[thenoxus1]

My GSR is throwing a CEL for the O2 sensor, I was wondering where the best place to buy this is? (Not sure if I posted this in right forum) I was told there are a couple of them, not sure which place to buy from, and how simple is it to replace?

 

[phatintegra]

Is your OBD1 or OBD2? If it's OBD2 do you know if primary (before cat) or secondary (after cat). Just one huge nut can't remember the size if it's 14mm or 16mm. There is a harness you need to disconnect that's on the OBD2 I think it's the same way for OBD1 as well.

 

[thenoxus1]

It's a 99 which is obd2 I think? Will the code differentiate which one? When I checked it at advanced, he just told me knock sensor and an o2

 

[mjones73]

It should, there's a primary and secondary. What code(s) do you have?

 

[j13]

if its the primary its really easy. Autozone sells a nice bosch one for 75$. if its the secondary than it is a little bigger job to replace.