m3clubracer

2010 G37x
I installed a set of Megan test pipe DP's - 1st mistake but cat was broken and rattling and these were CHEAP.
Throws a CEL but runs fine but rich.
Decided to get a set of 90 degree O2 sensor extensions to help turn off CEL and return to normal non-rich condition.
Decided to clean the sensors with carb cleaner like the internet says - 2nd mistake, I know to only change one thing at a time but ran rich like this for 9 months.
Dried them with a small butane torch for 1 min.
Installed them with 90 degree extensions.
Now have P0301 code/misfire cyl 1.
Tested the ohms and got 3-5
Can't get voltages while heating them, don't if I am doing it right, I hate electronics.
Swapped the sensors cross car - no change
Removed the 90 deg extensions - no change
Am I looking at getting another set of O2 sensors or will they eventually dry out?
FML

BULL

Carb cleaners dries out almost instantly, at this point it sounds like one if not both sensors are damaged. The real way to test them is with them plugged in and checked with OBD.

m3clubracer

Thanks. Carb cleaner should not have damaged them and the heat should have cleared out anything soaked in. They were fairly new and nothing deteriorated or broken. Was very careful in R/R. I was so mad I didn't even try checking with Dashcmd. I will try tonight. I have old logs from a long time ago.

BULL

There is a breakdown on the FSM on how to diagnose faulty O2s.
You'll need a multimeter and OBD capabilities.
Measure resistance across the circuits of the sensor and observe their voltages through OBD.
The FSM will let you how to move forward based on your findings until you find the fault.

m3clubracer

From my Dashcmd voltage readings...




From the FSM...which one is bad??

BULL

In my opinion, Bank 2 is the issue.
Detecting higher steady voltage equivalating exhaust leak or lazy sensor Since it's steady and never dips.
Now that you have this info, switch the sensor around and compare.
If your readings on Bank 2 with the switched sensor then your issues dont appear to be the sensors.

m3clubracer

Agreed. I have two NTK sensors for &70/ea coming tomorrow. If that doesn't fix it then its in the connector which was a b!tch to get out.

m3clubracer

Been geeking out over the data and overlayed the RPM and it looks like both aren't working that well.

BULL

Prior to anything switch them, you need to confirm the same but opposite readings when you swap them. Rule out exhaust leak since they both affect the reading.

m3clubracer

Yeah I need to switch them again and read banks. The damn interface doesn't split the bank readings. I just installed those 90°fittings



and the O2's and turned it on and the miss happened. I just last week had a new exhaust welded up (Speed Culture Studios setup) and the exhaust shop told me I had FOUR! nuts (top 2 per side) missing off my DP's and yeah thee was a leak then. I checked the rest and it's good. I had a big leak at the end of the Y pipe about two months ago and fixed that. Nothing ever screwed my miss like this. Also changed my plugs 12-8-21 2k miles ago. All was good until I soaked and cleaned with carb cleaner. I'm receiving the NTK's today and they BETTER fix it. I will look at the connector again on bank 2 again and maybe try and see if there is any voltage, but from above, I don't think that is a problem. The B2 wild swing may be due to the connector. I do have 1" extenders for the sensors but they are for the kind with short snouts. I will have to drill them out to make the sensors fit. Can see them on the ends of the 90° fittings here.



You can see that the 90° have restrictors and they sent me 3 of the large size.

m3clubracer

New O2's are no dice. I'm swapping coils and looking at spark plugs. If that doesn't do it then it's the connector on B2S2.



Also installed the 90° fittings and drilled out the spacers for another 1".

juster

You need a tune to run with test pipes. Stock ypipe is also restrictive with test pipes. Spacers won't work I tried them all. ECU uses rear o2's for fueling sometime I don't know the details why. Your tuner can turn them off but she will run better with a matching tune to the exhaust. Oh yea and make sure there are no leaks. Use some ultra copper on the test pipes.
My experience.

m3clubracer

I replaced the entire exhaust about 3 weeks ago (see above) due to rasp. The DP's and new Y pipe have been on there since 3-29-21 at 208k. If I have to get a tune I will just go get Berk cats, still too loud. I removed the plugs on the bank 2 - 1/3/5 side and they were all burnt to hell! See the top plug in pic. They were installed 12-8 at 220000 miles and replaced the bottom ones that had 110,000 miles. Both are the same NGK plug. I swapped #1 and #3 coils and the miss moved from 1 to 3. Not the sensors. Will go to pull-a-part tomorrow and get a couple coils. The car has 224,000 now and this is the first thing that has failed on it's own (exhaust rot doesn't count since it lived 8 years in salty north) that I or someone didn't provoke. I live near Soho Motorsports and might tune if it helps the plugs. It just is a very low HP return for the money. I gave up and took it to a local shop. I don't do electrical.

m3clubracer

>>>UPDATE<<<
Installed 6 new coils and plugs, 90° fittings with spacers drilled as above, two new NTK O2 sensors. No more miss or CEL after 9 months of living with it blaring on the dash and rich condition! Still rich though 12.2ish/no cats. Coil was diagnosed when swapping to #3. Pulled out 110k plugs on 1/3/5 bank and they looked normal. 225k miles and still pulls like a champ!!!. The coil is the only thing that has failed on the car in quarter mill miles! Nissan (Japan) reliability rocks!! Just hope my F80 is close to this standard...