MaxxAddict

So frustrating. Was counting on getting ride of this code after I installed the right rear O2 sensor (one by the firewall). Welp, It's baaaaack........

Any ideas? Thanks.

EDIT: btw, I did clear the CEL soon after I completed the installation. My understanding was that it isn't supposed to return. Guess this case is different.

99BlkSE5spd

thats wierd...

Chickan

iTrader: (12)

check your fuses, it seems pretty common that the fuse blows, causing the CEL.

MaxxAddict

Thanks chickan, I'll look into that. Any other ideas? Should I disconnect the battery to reset the ECU instead of using that screw turning method?

MaxxAddict

welp, checked the fuse. No prob. Wasn't broken/cracked/burnt. I reset the ECU via diconnecting the battery. i HOPE the CEL doesn't come on. If it does, I dunno what else to try.

njmodi

iTrader: (4)

You might need to check the main harness.

MaxxAddict

ok. How does one "check" the main harness? Somehow hook up an ohmeter? (sp)

Seyser

do maxima's have both a CEL and SES light?

MaxxAddict

Please don't post stuff like this in my thread. thanks.

CEL = SES

MaxxAddict

BUMP. The CEL returned today. Any other suggestions??

Was nice driving around without it for about 120 miles. I filled the max up and calculated almost 32mpg!!

99Automagic

I wouldn't go changing out the o2 just because I have the cell a few times. Here is my reason. About a little over 2 months ago, my o2 cells were popping up randomly. There were two of them, front/bank1, and another one, some high voltage thing, I don't remember. Well, after resetting the light about 15-20 times, I haven't gotten a cell back yet. During that whole time, my mpg never suffered, no loss of performance, and the car was running great. I have yet to see the light return and everything is well.


You guys know how freaky our o2's can get. Anything could trigger that foken code. I'm thinking some carbon might stick to the sensor, trigger the cell, then later on burn off.

MaxxAddict

hmmm, carbon stuck onto it? Possible I suppose

Anyone else have any suggestions?

killcrap

iTrader: (3)

DTC 0409

Diagnostic Trouble Code 0409 indicates a problem with the front Oxygen Sensor on the right cylinder bank.

The right bank is also called the rear bank. It is cylinders 1,3,5. The Engine Control Module determined that the response of the voltage signal from the sensor takes more time than it should. In simple terms, the Oxygen
Sensor is still working but it is not doing its job well. Possible causes include ...
- Harness or connectors (the sensor circuit is open or shorted).
- Bad Oxygen Sensor sensing element
- Bad Oxygen Sensor heater
- Fuel pressure out of spec
- Fuel injector malfunction
- Intake air leaks
- Exhaust gas leaks
- Positive Crankcase Ventilation valve
- Mass Air Flow Sensor



The Oxygen Sensor sensing element may be tested with an electronic tester made for this purpose, or with an
automotive oscilloscope. The Oxygen Sensor heater my be tested with an ohmmeter. This test is done with the
engine off. Follow the wires away from the Oxygen Sensor until you find the nearest electrical connector. Disconnect theconnector. Viewed with the connector latch at the 12 o'clock position, there are three terminals.

They are numbered 1-3, right to left. Be sure to measure the terminals in the connector half which is attached to the
Oxygen Sensor, not the one which leads to the Engine Control Unit.

Measure the resistance between terminals 1 and 3.
The factory spec is 2.3-4.3 ohms at 77 degrees Fahrenheit.

Measure the resistance between terminals 1 and 2.
The reading should be infinity (no connection).

Measure the resistance between terminals 2 and 3.
The reading should be infinity (no connection).

MaxxAddict

Killcrap: Thank you very much

All: Which scenario mentioned would y'all say is the most likely cause of the o2 sensor CEL? Which would you say occurs most frequently, and therefore, should test for first?

pedroboe

I had a similar problem last week. After changing both left and right upstream sensors I kept getting code 1001, the left sensor. I took it to a guy who replaced 2 other sensors thinking it would make it go away.... 400 dollars later, i still had to shell out $135 more for that left sensor, which was brand new and defective. It was also a generic one...
I would just get another sensor , preferably a genuine Nissan and see if that helps before going with other time and $$ wasting adventures. The computer usually doesn't lie.

killcrap

iTrader: (3)

bosch is oem www.oxygensensors.com get % off mention maxima.org

hacim105

iTrader: (6)

You know there are times when there is something causing the CEL to have a complaint about an O2 sensor other than the O2 sensor being bad. That's why the CEL exists.

s600ergy

read this i hope it will help,read evrything
http://forums.maxima.org/showthread.php?t=417379

MaxxAddict

I already checked the fuses. No prob there.

I'm not gonna buy a new O2 sensor. I'd rather check it with an ohmmeter first to see if it's busted before I go and blow another $60.

MaxxAddict

!!!

I checked the O2 sensor with a ohmmeter. I followed the instructions exactly and discovered that resistance between terminals 1 and 3 is 0 ohms!! ZERO!!

So I assume this means that all I need to do I purchase a new O2 sensor harness and wire it to the old O2 sensor? Any know where I can buy a new harness besides some stealership? I checked buyoxygensensors.com, ebay.com, and jerryromenissan.com but to no avail.

Thanks!

EDIT: Is the info regarding the 2.3-4.3 ohms correct? That seems like an extremely small number. Some ohmmeters aren't even that precise! Many just give readings in precision terms of 1000s.

MaxxAddict

IMPORTANT: I'm a

Turns out I bought a multimeter that wasn't as precise as I needed it to be. So I purchased another one (which wasn't as cheap). And now I get the following results, which I believe to be correct:

Recently installed O2 sensor harness reading: 6.6 Ohms

Could this be the cause of the problem? Would 2 additional Ohms of resistance above factory spec cause the O2 sensor to not send the right voltage to the ECM?

I also checked the reading on the old harness which I removed when I installed the new O2 sensor. This is the reading I got:

Old O2 sensor harness: 4.3 Ohms

Should I just swap harnesses? Basically, use the new O2 sensor I bought, but use the harness on the old, dead O2 sensor? How do I go about swapping the harnesses? Could I just cut the harness wires and then solder the old harness wires to it (so as to use to old connector?)

MaxxAddict

Come on guys. Does anyone know?

MaxxAddict

bump....

MaxxAddict

I recently replaced my O2 sensor and reset the ECU, but the code keeps coming back

I call up the stealership complaining about the 0409=P0133 code and the guy says I need to bring it in because Nissan dealerships have a "special program" which clears the ECU memory. He says that he gets mechanics calling him up all the time asking the dealership to reset the ECU.

I ask him why disconnecting the battery won't work. He says that it just won't. I THEN ask him about the reseting the ECU via the self-diagnosis mode with the screw. HE HAD NO IDEA WHAT I WAS TALKING ABOUT!! :

I asked him (just for curiousity sake) how much the reprogramming would cost and how long it would take. He said 1 hr long and $82 fee!!

I needed a good laugh today. Just thought I'd share.

Jeff92se

iTrader: (82)

OBDII scanner should be able to reset the CEL. Was it a CEL or just a ecu stored code?

MaxxAddict

How do I tell the difference?

What is the difference between reseting the ECU with the OBDII scanner vs. the self-diagnosis screwdriver method?

Jeff92se

iTrader: (82)

Dunno. Was the cel light on or not? I just reset my dad's cel light on his Toyota using the scanner. But I could not erase a stored DTC code on my bro's Nissan Exterra. But he had no cel light.

MaxxAddict

When I reset the ECU with the screwdriver method and unplug the battery, then check for codes, I get 0505-no malfunction.

When the CEL comes back on (usually 50-100 miles after I perform the above mentioned steps), I perform the self-diagnosis and get 0409 code.

The process continually repeats itself.

Jeff92se

iTrader: (82)

Looks like the ecu is still seeing an out of range voltage from that 02 sensor. But it could be the harness like you mentioned. If the new one ohms out of spec, you should return it for a new one. It usually takes xx miles for the ecu to flip the cel light again after resetting it.

MaxxAddict

How and where abouts do you disconnect the old harness and connect the new one? Maybe a pic of a universal O2 sensor and an OEM one would suffice?

Also, how do I know if the new O2 sensor I purchased and installed isn't a dud? I have a multimeter. Anyway to use that?

BTW, thanks for the help, Jeff.

packetscan

Yikes your not useing your a/c huh?

I'm running about 20 mpg right now..

Yet i had a weight problem with my right foot.

Jeff92se

iTrader: (82)

This might help. Pics are from a 3 gen but since it mentions front/rear etc... the info pertains to 4-gen

http://www1.autozone.com/servlet/UiB...3d801f4e84.jsp

MaxxAddict

Thanks for the pics. The O2 sensor w/o the harness is as I thought it was.

Here's the deal. I checked the resistance on the new O2 sensor and harness combo I installed. I get 6.6 ohms. Ok. according to that autozone link, I have a faulty O2 sensor (the new one is a dud).

BUT when I tested the old O2 sensor and the harness attached to it, I get 4.3 ohms which is between factory spec. Therefore, maybe the heater on the old O2 sensor is fine (4.3 ohms), but the old O2 sensor itself is busted??

So...last night I spliced the wires and connected the old O2 sensor harness to the new O2 sensor unit I installed a few weeks ago, HOPING that the harness was indeed the problem. Sure enough, I am STILL getting a resistance of 6.6 ohms.

s600ergy

guess what cel came back today after driving on the hwy 55 mph for about 2 minutes. why?

killcrap

iTrader: (3)

what did you expect? that just switching the wires will fix the problem? of couse not. the wires on the o2 sensor are not resistance wires, they should not have any resistance in them. if resistance specs on 1-3 are bad, replace the sensor. stop wasting time. if you want to check for high resistance in the wires, switch your multimeter to ohms, and backprobe into the wire nearest to the oxygen sensor and put the other lead at the harness. should be .1ohms-.4ohms indicating continiouity with no resistance.

oh and btw, there are two types of codes, a hard fault and a soft fault. a hard fault will stay in the ecm and will go away if you fix the problem, and reset the code. a soft fault is a code that has been detected by the ecm at a certain point. like an o2 sensor. you do not use the o2 sensors for start up, of couse the o2 sensor will still give cross counts at open loop. the ecm just ignores it until TIME, TEMP and o2 switching has occured.

the dealer was basiclly lying to you, and said they could only reset codes. anyone can.

your o2 sensor light will probably go off at a certain speed. because there are monitors on your ecm to detect emissions failures. i'm assuming your catalyst monitor is NOT READY. they usually go off at cruising speeds 40-80mph for a couple of miles.

MaxxAddict

WOW!!

Killcrap, you basically solved my problem completely!

So in short the new Walker OEM o2 sensor and harness combo I purchased from buyoxygensensors.com is a dud. Too bad I already installed it; now I can't get my damn money back! I'm gonna call them up and see what they can do for me. Maybe a semi credit to my account?

Also, forgive my o2 sensor experimenting. I'm a noob, I had no idea what I was doing, and no one was answering my posts. I had no other choice. It was worth a shot I figured.

I'm not sure about my O2 sensor light going off at a certain speed. I never really took notice. But one thing is for sure... I can usually get >50 miles of driving before the CEL reappears after being reset.

QUESTION: When I measured the old o2 sensor resistance between terminals 1 and 3, I got 4.3 ohms. How come? Was the old O2 sensor working fine? Did something else trip the CEL with the old O2 sensor?

Please bare with me on these questions. I'm still trying to learn. Thanks!

killcrap

iTrader: (3)

your old oxygen sensor was probably still good, other things can cause the 0409 DTC to show up. it could be bad though, you would only be able to find out using a scanner. you would check the cross counts. normally it would be 10 crosses per second i think. if the pcm saw that it was slow, it would move the sensors STFT over, and if it were over the limit, it would move your cars LTFT up to the next bracket.

if your o2 sensor is more than 80K, i would replace them.