It finally happened, P2A03 code showed up.
I have a ELM327 OBD2 connector, so i am trying to get some more data.



First thing, there is a big difference in the O2 value between sensor 1 and sensor 2 on bank 1.
Sensor 2 is a lot richer, sometimes so rich the code P2A03 pops up.



These are when i rev the car, it looks like both O2 sensors are responding to the change in rpm.



I need some help where to start, what could be the problem.

Faulty O2 sensor, but then, is bank 2 or bank 1 failing?
Air intake vacuum leak ? (on bank 1, because this is lean?)




Found this image online, but it is from VQ37VHR ( I searched the G35 manual for this image,but i can't find it)
I expect VQ35HR to be the same, so drivers side manifold sensor is generating the code

 

Start by checking for obvious vacuum leaks, remove both intake tubes and visually inspect for cracks/rips/tears. Pay particular attention to the corrugated flexible sections.

Next check the PCV hoses, they will attach to intake tubes, valve covers, a bypass from one valve cover to the other, and a return to the intake plenum. Make sure each hose is TIGHT at it's fitting, you should not be able to spin the hose by hand without a lot of pressure. Also unscrew the PCV valve and shake it to make sure it still rattles, if it has seized up you can clean it with brake cleaner while it is uninstalled from the car.

Also clean the MAF with some MAF cleaner spray, do both of them.

If you're sure there are no vacuum leaks and the MAF's are both cleaned then it's PROBABLY the O2 sensor, that code is bank 2 which is the left side. I don't know which side the steering wheel is in the Netherlands so "driver side" might not be the same as other countries, it's the left side though. In the USA with a left hand drive that would be the driver side.

That code can also be caused by fuel delivery issues but since you're only throwing the code on one bank I suspect it's either a vacuum leak or a dirty MAF.

 

I will check all hoses and intake tubes tomorrow.

Just to check, can i switch the PCV valves th the other bank?

About the MAF, how often do they fail?
I tried to check MAF flow with Nissan datascan 3, most of the time it looks ok.
Right screenshot has some differences, but i think this has something to do with refresh time of the data,



On my previous O2 sensor screenshots the second O2 sensors on the cats were not showing any data, i made a few extra screenshots while driving.
On this screenshots i see the drivers side O2 bouncing a lot, what is normal, bank 1 or bank 2 ?

 

Your bank 2 is the good/normal one, it should be fluctuating high/low/high/low at idle. If it's not then it's probably not working correctly, judging from those shots you posted it looks like you have a bank1 sensor problem.

Here's a random picture off the internet, see how his bank 1 (red line) has a lot of very spiky peaks/valleys. That's what you want to see, his bank 2 sensor (blue line) is VERY lazy when compared to bank 1.

 

I just realized I was looking at your bank1/2 sensor 2 data.

Only monitor the bank1 sensor 1 and bank 2 sensor 1 data.

 

All 4 sensors are in the data,
1x1 = bank 1 sensor 1 - 2x1 = bank 2 sensor 1
1x2 = bank 1 sensor 2 - 2x2 = bank 2 sensor 2

When i look at your picture, the sensor 2 output should be very stable, and sensor 1 output should move a lot.
My data is differend, sensor 2, bank 2 is moving a lot.


Tested so far:
I have checked for vacuum leaks, nothing found.
I cleaned the PCV valve, no difference.

I hope it is one of the first sensors, but is it bank 1 or bank 2?

 

Ignore all the sensor 2 stuff, that's just catalytic efficiency and not your air/fuel sensors which are the sensor 1 data.

The resolution on those little graphs is terrible though, if you have an android phone and an ELM32 Bluetooth OBD2 adapter you should try out the app Torque Pro it's gives MUCH better sensor resolution.

 

And don't check the stuff while driving, just let it idle in park/neutral and test the O2 sensor data.

 

The previous displays are made with torque free, these are made with torque pro
I tried to get both sensors in 1 screen, but the app wont let me do that.
All data is made at idle, like you told me, hope it shows something for you.

Cold engine




Warmed up:

 

Clear the codes, try to narrow down EXACTLY what makes it trigger. I suspect it's only going to throw the code on a cold engine. Keep your BT adapter and stuff in the car so you can clear it when it pops up if it does it cold, then see if the code comes back when the engine is already up to temp.

When the O2 sensor heaters are on the verge of failing you can get codes like this and that's what I'm starting to suspect.

 

Code has only showed up 3 times, only on cold engine.

Wich sensor to suspect, bank 1 or bank 2?

Still looking to fix the problem, but also busy with lots of other things.

 

P2A03 is bank 2.

Bank 1 would throw P2A00.

I know O2 sensors aren't cheap but it would be a good idea to replace both banks since they don't last forever and one is already showing possible signs of malfunction.

 

I am trying to get the right OEM part number to buy new O2 sensors.
Lots of websites are showing sensors with the wrong connector, for 370Z/G37
i think my OEM part number is 22693-ZE00A, my car has this O2 sensor / connector.


I am looking for a alternative brand O2 sensors, i heard Bosch or Denso are okay.

For Denso i can only find 1 number, Denso DOX-1447, but i am not 100% sure it fits, it looks the same.
I also found Febi Bilstein 177523, a match on the OEM number, but i am not sure about the quality of this brand.
It looks like Bosch number is F 00E 262 952, but i cannot find these sensors for sale online.

 

I ordered a Yato O2 removal tool, it arrived yesterday

Today i switched out the sensors between bank 1 and 2.
It was not as hard as i expected it to be, with the right tools i think it can be done in 1 hour.


After reinstalling the O2 sensors i expected bank 1 to be richter now, and bank 2 should be more lean.
Strange thing, this did not happened, O2 values are still the same, bank 1 a little lean, bank 2 a little rich.

So the sensors seem to be ok, but i will check the sensor values again tomorrow, just to be sure.
What else to check now, i am starting to suspect a vacuum leak.
I could not find a vacuum leak myself, would a smoke test work to double check?



I took some pictures, just for fun.
Both O2 sensors are OEM (Denso) 211200-7020
I tried to clean the text on the left one, but after that most of the text was gone.