Meaning if I were to replace one, does it matter?

I'm looking at AutoZone right now for a replacement primary o2 sensor and it seems there are different part #'s for a before cat o2 and an after cat o2 sensor.

I'm also seeing heated and planar being referred to. Anyone know what that means?

 

the primary o2 is a narrow band A/F meter. the secondary (post cat) monitors the efficiency of the cat.

the reason for heated o2 and planar o2 refers to the heater element for the o2 that helps get the o2 up to optimal operating temperature faster during car warm-up so it can do its job better. you should most certainly have heated o2's on your car. planar would most easily be described as an older 2 wire o2 from say an old OBD1 car which has no heater element.

 

I am almost positive technically there is no difference in the sensor its self on our car. the reason you get different part numbers is because the pigtails are different. One has a femal connection and one has a male connection. I dont remeber which is which because I havent been under the car in a while. If I remember both are heated as well. I can guarentee the front sensor is heated though.

If I am wrong someone please correct me.

thanks

 

thanks for the explination on planar vs heated

yeah I know the o2s have different functions as far as tuning goes but didn't know if they physically were the same or not...

I guess my next question is does anyone have a primary o2 for sale? damn, these things are ridiculously expensive!

 

yeah they arent cheap, i think you can get it from gm parts direct for the $63

 

oh really? i'll pay that...the ones I was seeing were like $100+ so that sounds alot better