Thought I had things squared away but I got a SES today on the way back from LKQ or whatever its called. It was Pic-A-Part in my z31 and s30 days. BTW the driving/fog lights are great. Makes me feel even cooler Also discovered my front side markers aren't hooked up. Never were. I turned the fog lights on and only one lit up. I probed around and found another connector bundled away down there. I wired the connector on and voila.
Anyway... my scanner says no fault codes but 2 pending codes: P0138 and P0139. Bank 1 sensor 2 circuit slow and voltage high. I'm hoping just a bad sensor not a fuel issue. It's tempting to buy a cheap one since it's a downstream sensor but a good one is just $20 more. I just read through a confusing thread here on o2 sensor names and locations. I think parts makers had a lot to do with the confusion. Upstream/downstream, left/right, bank 1/bank 2, Cali has 4 sensors but federal only has 3 etc etc. FSM adds a little more confusion. I found a diagram here somewhere but I think it's wrong. I made my own crude diagram. If it's correct maybe it will help someone in the future.I used Denso part numbers. Also a short vid for people who just need to see it in person.

 

That pretty much looks right. Bank one is by the firewall with bank two by the radiator. sensor 1 is upstream and used for tuning the AFR. Sensor 2 is downstream and only trips the CEL.

 

Looks like a 3 year old drew it but it's close enough for rock and roll. I looked on rockauto for the sensor I need and it was crazy. Every brand had a different way of saying the same thing. Probably makes ordering the right one really hit or miss. Amazon turned out to have the best price. That's the second SES I've got in the short time I've owned this. The first was for the bank 2 pre cat. That was an easy fix but a little pricey. It's all been a nickel and dime (and a couple of quarters) experience so far. I'm sure that mid pipe cat is going to go soon and that looks expensive. The car runs and drives great though.

 

If you go into the sticky "5th Gen General Information, Maintenance, and Common Issues", and scroll down a little, in post #1 is a diagram of the California emission exhaust system points out the O2 sensors and the associated codes the might throw.

 

Oh yeah, that's perfect. So it's already been done and done better. Whoever made that also included all the different part descriptions. The thread I went through created more confusion than clarity. This deserves to be posted in any o2 sensor location thread so...

 

Carmen Sandiego stole em.

 

there it is

 

Go to rockauto and buy all new ones!

 

Can't afford to do that. I'll replace them as needed. I bought a new B2S1 the last time I got an SES code but the problem was actually the B2 cat. That sensor was $16 for a Denso on Amazon. The cat unfortunately cost a lot more than that. I found the cheapest B1S2 on Amazon too. I usually find the best prices on rockauto.com but not always

 

I wound up w/ an extra o2 sensor. If child of korn hasn't convinced everyone that o2 sensors are unnecessary evils (I'm not going to have that discussion) and you need this one I have an ad the classifieds for it. It's only good for 1999-2001 Infiniti I30 and 1998-2001 Nissan Maxima.
NIB Denso 234-4776 direct fit

 

 

so florida dosent have emissions?

 

I don't think they even have state inspections down there.

 

Well yeah, it's Florida for gawds sake lol. In Texas we used to say thank god for Mississippi because MS kept us from being last in things like education, unwed mothers etc etc. Now it's thank god for Florida I was talking to my gf the other night. She lives in Zurich but she's from Romania. She said something I thought was funny... Romania is the Florida of Europe. Seriously, I don't know if o2 sensors are going to save the planet but when they go bad or aren't there it make my SES light come on and anything that does that is getting fixed or replaced. Compared to a lot of cars I've owned, replacing the sensors is easy and pretty cheap. What anybody else wants to do about o2 sensors is perfectly fine w/ me.