Fakie J Farkerton

iTrader: (51)

schmellyfart

iTrader: (46)

Lets start at square one. What exactly have you tried?

Bonka

iTrader: (13)

OK based on my PMs with him, he followed my instructions posted earlier in the thread.

However looking at the ECM diagram pin 114 was blank for him when it's not suppose to be on the schematic so he used the female connector on that pin for pin 112.

He's using pin 108 for ground.

TurboA32

iTrader: (36)

Pin 114 is one of the emissions parts that my 95 ecu doesn't use so I used that female connector to put into slot 112 so I can connect a wire and tap into 108 to make the ground for 112 and the code comes back. And I even used a 95 engine harness which I shouldn't have to do any pin swaps being that it should already be setup for the 95 ecu and I still get the code....maybe my sensor is bad after 1 year but I don't remember getting this code with my 97 ecu with the pins lined up the correct way for a 97 ecu

Quickywd01

iTrader: (16)

They just mad they ****'s slow. Just kidding. Perhaps you can try a cheap ~$20 new 02 sensor just to see what happens.

TurboA32

iTrader: (36)

Just to confirm being that I have a 95 harness now there is no need to move any pins correct?

schmellyfart

iTrader: (46)

All nonsense aside, am bumping this thread since I finally had a chance to repin my 97 harness for a 95/96 rear o2 sensor.

Vehicle harness: 97 SE built in late 96.
ECU: 96 5MT Nistune'd ECU (Also have a 95 5MT Nistune'd but havent tried it with the repin yet)
Pins 107 and 105 swapped, pin 112 grounded to pin 108, P0136 still comes back.

I have no catalytic converters. Never threw a rear o2 code with the 97 ECU and no cats. My thoughts are maybe the 96 ECU is more sensitive about the cats than my 97 ECU? I am going to reach into the bag of 5th gen header tricks and try installing an o2 sensor spacer/spark plug antifoulers and see what happens. http://www.ebay.com/itm/O2-OXYGEN-SE...bfa286&vxp=mtr

Fakie J Farkerton

iTrader: (51)

Looks like I owe a couple people in this thread an apology.
Sorry guys.
Looks like real world testing is needed.
Hopefully the extended bung works.

Finkle

As long as we are on this topic, I have a dumb question.
What is the advantage of putting at 95 ecu into a 97 assuming both are fed spec? I have seen people change out the 99s to get rid of NATS and other annoying things, but is there any big difference between a 97 and a 95 performance wise?

Curious as I have a 97 and if it helps anything, I can probably find a 95 ecu in the jy for a song

Fakie J Farkerton

iTrader: (51)

^Read the posts in link 4.

There are no performance upgrades switching OEM for OEM, it's just getting rid of codes.

TurboA32

iTrader: (36)

My main reasons for using a "early federal emissions" 95 ecu is for the less emissions parts. The 96+ maxima's come with emissions parts such as purge valve and the famous evap canister in the back of the car near the gas tank which the early 95 federal emissions ecu don't have. if you have those codes you wont pass emissions and can be expensive if you take it to get fixed. And the 95 ecu can be used for adding a stand alone like nistune or JWT boards for performance reasons. So in my opinion where emissions testing is done its worth it

Finkle

Got it, thanks TuboA32
I couldn't pick up in the posts if there was another reason besides the emissions as to why the 95 was the highest valued ECU to have. I don't have emissions testing, so no need to worry about that troublesome CEL.

Crusher103

iTrader: (10)

Careful swapping those harnesses. Nick(95maxrider) just had issues swapping harnesses. There are some running differences between the 95 harnesses vs the rest of them your car may not start using the older style harness. Stick to your OEM harness and just mod it to work.

TurboA32

iTrader: (36)

No problem. They consider the 95 ecu "gold" for the less emissions parts and the only other reason a 95/96 ecu would benefit over any other year ecu would be that you can put a (daughter board) = "standalone" into a 95/96 ecu for performance tuning and have a more factory direct tune like a dealer consult as to 97+ ecu's you would need a "piggyback" wired into the ecu harness and try and trick the ecu into believing the tune and sometimes the ecu tries to correct itself when you put a "piggyback" into the harness which can sometimes lead to the car not running properly.

maxprivate

iTrader: (12)

ok so I moved pin 107 to 105 but pin 112 there is no existing wire in that slot.. in order to ground 112 I need one of those pin connectors to insert a wire into that empty slot on the ECU harness plug then I can just ground that wire.

I tired Radio shack for that type of pin, was a no go.. Anyone know where I can get those metal pins.

maxprivate

iTrader: (12)

Anyone that's has done this? Would like to know what route you took.

schmellyfart

iTrader: (46)

I have an auto ECU pigtail, and just pulled it from one of the slots not needed for a MT ECU, then soldered the wire to an existing ground.

maxprivate

iTrader: (12)

Got Ya.. that's what I figured. I was able to get some ecu pigtails from a spare harness. I have a buddy that works for Nissan luckily he had an entire engine harness.

schmellyfart

iTrader: (46)

Quick update. P0136 remains with the antifouler installed.
Next up is a 95-96 rear o2 sensor.

luke95gxe

iTrader: (4)

i have very early 95 ecu im running in my 97 fed spec i was bout to try this deal Leonard please keep us updated.
im auto though

luke95gxe

iTrader: (4)

i have very early 95 ecu im running in my 97 fed spec i was bout to try this deal Leonard please keep us updated

darklegend06

iTrader: (11)

I have a 95/96 ecu in my 97 maxima. I rewired the pin and I have no problem with trouble codes.

I don't remember what I did exactly, but I can tell you I have a 97 o2 sensor. Let me retrace my steps and see if I can remember correctly before I write the instructions.

For those that are wondering why I have a 95/96 ECU is because I did a 5spd swap several years back.


EDIT**

After looking through the FSM, which I'm not sure if you did; the 1995-96 ECU pins for the rear o2 sensor is pin 105 which should come from pin 1 on the o2 sensor.

The 1997 wiring to the ECU for the rear o2 is pin 107, so if you don't switch the pin from 107 to 105 the 95/96 ECU will throw a P0136 or 0707 code.

Also the 1997 up o2 sensors only give out approx 1Volt versus the 95/96 are expecting around 2.2 volts.

Further more, the o2 sensors for the 95/96 are three wires out and the 97/98 are four wires out.

Lastly, and if I remember correctly 95/96 rear o2 has a smaller bung hole compared to the 97. (don't quote me on this one, haven't worked on my Maxima for over 2 years)

schmellyfart

iTrader: (46)

Anyone know where I can get the rear o2 sensor for fairly cheap? Lowest I'm seeing is $40 on rockauto.

luke95gxe

iTrader: (4)

my info says to swap 107 to 105 then ground pin 112
schmelly is that the way you wired yours

maxprivate

iTrader: (12)

Hmm converted to auto 95 ECU from Cali spec 97


I did the pin out swap for rear 02 but I grounded to a different spot on the ECU harness... Didn't use 108 Never got a code for it. Maybe I didn't drive around enough?

schmellyfart

iTrader: (46)

Yes Luke.

Where did you ground yours maxprivate?

darklegend06

iTrader: (11)

quick question for you... did you try what I mentioned in my post? I've been running like that for 5 years or so without any problems.

Grounding pin 112 might be a good idea, but I don't remember grounding it on mine.

maxprivate

iTrader: (12)

I grounded it to one of the other grounds on the ECU where several other grounds already existed but it was not 108.

So you say you removed pin 114 I did not do that, left it alone. I used a spare pin a friend of mine gave me from an old harness... plugged that into 112 and soldered that wire into another ground source. Never got the code. I'll let you guys know if one ever pops up but you should be good if you do like I did. Don't cut any grounds just strip the wire insulation off and solder on to it tape it up well and you're done.

YuP, if you look at the ECU diagram 95 96 ECU 112 is grounded for rear 02 sensor. But I guess if you didn't get the code leave it alone.

TurboA32

iTrader: (36)

The cheapest I found was on ebay for $46 shipped so 40 bux is the cheapest you'll find it they cost double at autozone and advance autoparts

TurboA32

iTrader: (36)

If the o2 sensor voltage is different i don't see how it would work with the 97 sensor....and another thing i don't understand is why ground pin 112? It isn't coming from the 02 sensor so how is that gonna work the sensor needs to be grounded...im gonna cut the harness and use a 95 / 96 harness with the 95 /96 sensor and i will report back with results

schmellyfart

iTrader: (46)

Yes I did, I mentioned the wires I swapped a few posts back.
Would you check the pin number for me? I never touched 114, that was turbo A32.
Pin 112 is the rear o2 heater GND, And I'm trying it with the 97 sensor because its worked for some people and is cheaper than buying a new sensor.

maxprivate

iTrader: (12)

when I get my car back.. I can check but it's gonna be a while. In the middle of a 3.5 swap.

TurboA32,

My thoughts on grounding 112 even though it's not coming from the 02 is simply because the 95 96 ECU is looking for a ground.. I'm betting since it doesn't see a ground after swaping from a 97 ECU which doesn't require a ground on that pin, the 95 96 ECU will throw a code.

Try looking up Eng92 thread on his finding with this very same issue. He tried different rear 02s and if I'm not mistaken it was his findings originally to ground 112 and pin swap keeping the original 02. I could be wrong but check out that thread it should help answer some questions.

TurboA32

iTrader: (36)

Thanks for the reply I'll try looking for that thread. But where is the ground for the rear o2 sensor on the 97 looks like it doesn't have one

maxprivate

iTrader: (12)

No problem and I agree, I don't see a ground on the 97 ECU for the rear 02.. It maybe grounded in the 02 sensor itself therefore not needing a ground anywhere else. Just a hunch but seems like thats the only logical reason we see no other ground on the 97 ECU for rear 02. Remember 95/96 rear 02 and 97 rear 02 are two different 02 sensors. Keep that in mind.

Fakie J Farkerton

iTrader: (51)

There was a ground strap connected by my cat on my two '97's and iirc that is the rear O2 sensor ground.
Could be wrong, but I wanted to offer the info.
I haven't worked under any other years to know if they all have a ground there or if it's a 97+ change and I may be way off considering you're discussing the ECU pins.

TurboA32

iTrader: (36)

I found this link where someone posted that the exhaust ground was for the o2 sensor post #10

https://maxima.org/forums/5th-genera...aust-wire.html

schmellyfart

iTrader: (46)

Been a while but I figured I'd update with some closure.

1995 MT Nistune ECU in my 1997 3.5 6MT, all monitors ready and no codes.

• No Cats, no EGR, all other emissions components connected.
• I used a new 1995 NTK Rear O2 sensor off of Rockauto.
• M18 to M12 adapter to use the 95 sensor in my stock exhaust.
• Swapped pins 105 and 107,
• Added a ground wire to 112 and ran that to the ECU Case and one of the ECU bolt holes on the body as my ECU is currently laying under the passenger floor mat.