Just like the title says. I tried searching on here and other sites and cannot find an answer. I recently have been trying to help a coworker with his Z that he is modding. He recently installed a COBB and it displays the AF ratio. He was told that the factory upper O2 sensors on the 350Z(2005-2009) were wideband O2's. In searching for replacement sensors I have found two different "factory replacements". One is a 5-wire (WB) and one is a 4-wire (NB).

So, is it true? Stock 350z's 2005-2009 have stock upper wideband O2 sensors? This sounds a bit odd to me, but I guess I would not be too surprised anymore.

If so, I ask the question why do FI guys on here then purchase an aftermarket WBO2 units if the stock uppers can just be utilized since they communicate readings to the factory ecu, or standalone and then logged using the accompanying software?

 

I dont think the factory O2's are Widebands. Im pretty sure that if they were we would know about it. Most of the tuners that have been working on Z's for years would know about it. Besides, what is the point of being cheap in a build? wideband kits arent that expensive.

 

I did not really think they were to be honest. Like I said, sounds strange to nissan to install WB's on a factory tuned car. But this coworker insists that someone from a reputable company told him they were. I tried searching all over, never found an answer (that also would suggest they are NOT widebands) but still figured I would ask the experts.

Anyone know for sure yes or no?

I know how expensive they are, I have one. But not on the Z. Trust me, I am not one to save money when it comes to a quality build. I have suggested this coworker purchase one for the best results (or get the car dyno tuned) but he is not able to spend the money at the moment.

 

from what I recall the ones in the headers are WB and the ones in the cats are NB. It may depend by year though. Some of those ECU readers will display AFR but only for some of the newer Z's.

 

That is what I was possibly finding and what he was told. But only in 2005 and newer Z's.

Can anyone else confirm this?

And again, if so, why do ppl still purchase aftermarket WB's for larger builds? Sounds like wasting money.

 

People buy aftermarket widebands in order to monitor the AFR with an independent gauge rather then using an all in one unit.