P0135 - Location/How to Access 02 Sensor for Replacement?
 

P0135 - Front O2 Sensor Heater (Bank 1)

I have the 02 sensor and want to replace it after work today. I have this diagram that shows me where it is basically but I wanted to know how you get to it (through the engine bay if possible or if I have to jack it up. It looks around the same height as the headers but it's hard to tell and i really hope you don't have to lower the exhaust at all to access it. Does anybody possibly have real pictures (not diagram) of it's location on the car? I rented an 02 sensor wrench set so that aspect is all set. Thanks for any help/guiding pics guys.

http://memimage.cardomain.net/member...8_250_full.jpg

I think you are referencing HO2S1-B1 (Black harness). If you look from the passanger side front wheel, at the left side of the wheel (turn the steering wheel full right for better view) at the back of the engine and above steering rack you should be able to see it. It happens that I will be replacing mine today too, though it is Fed spec but it happens to be at the same spot as yours. I plan to use only a 22 mm wrench and will just crawl under the car and reach it. If need be I may jack up just the passenger front end...

Thanks a lot. I'll try the same.

Front O2 Bank1 Sensor How-to
 

Just did it and took me about half an hour. Here is how-to: I did not jack it up, just threw a mat on the floor and reached for it. If you extend your arm behind the passanger tire you can reach it and most likely see it right in front of the steering rack. I used 22 mm wrench to take it out. The connector is on the top of cylinder #2, I think that's the one (first one in the back of the engine on the left hand side looking from the front of the car). Connector disengages if you push on the green spring loaded button of the connector. There is a plastic clip about 10" down the wire away from the connector that holds the sensor wire away from the exhaust headers and it is clipped in. You can just pull on the sensor wires and it will pop out. New sensor will have the same clip so just put it in the same place as the old one. And that's it :-)

you might consider dropping a few bucks on an o2 sensor socket too...

i use this one the most... get one like it.

http://buy1.snapon.com/catalog/item....re&dir=catalog

You might find this useful:
http://www.soundoff92.com/bpullen/P0135.jpg

I just changed one of mine the other day.
Just run the thing up on ramps or jackstands and you should have plenty of access.

The hardest part is feeding the wire through and getting it clipped in just right.
As you pull the clips out of the old one, pay close attention so you can get the new ones in.

Another O2 sensor trick: Before you put it in the socket, twist it a few times the other direction so the wires will actually straighten out as you tighten it.
Anti-seize compond on the threads is a must!

how much is the new sensor?

OEM is about $110... You can may be find them cheaper aftermarket or as a simulator...

www.oxygensensors.com

The Walker unit is direct OEM fitment meaning there is a harness and it's just plug and play. It was $80.91 with maxima.org discount. Just call them and ask. Installed mine yesterday with no problems and my engine light is now off...Finally.

or you can just tighten it before plugging it in.

It's easier to drop the sensor through the engine than trying to push the plug up. As a result, it's better to already have the plug in place (even if not connected.)
With the wire feeding through so many twists, it won't tranfer the turns up to the plug easily.
You can do it the other way, put preturning it just makes life easier imho.

just tu add to this post, I changed my O2 sensor (code was P0135) this weekend. Boy is it thigh in there!

I dont know how you managed to reach it without jacking up the car first, IGZY.

I also had to cut the wire of the old O2 sensor, since it was stuck and I could not take it out from the bottom nor from the top. wonder how it got there in the first place?!?

I reset the SES light by disconnecting the battery while I was doing the change.

Anyhow, jobs done now and it took me 1h and a half... im not that much of a mechanic, plus it was freezing cold outside and that 22mm wrench REEEALLY gets cold at those temperatures!
been 3 days and SES light is off.

now I hope my gas mileage will get better from now... I was pretty bad with the faulty O2 sensor...

I will post back in a couple of weeks to get back to yall about this.

Hehe, I am about 6'3" and have long arms and often work on blind and just by touch...

I know what you mean about cold. It is much colder in Montreal than in South-Central Ontario this time of the year... I did some work over past few days outside too and it was not fun... brrrrr...

I have the same code but the sensor seems to be working fine. For the matter of fact it works the best among all the sensors (o/p ranges from 0.2-0.8v).

Could a perfectly working sensor have the heater element not working?

Yes... Sensor has heater and signal lines... The signal could be coming in OK but heater may be busted and the code that you get would point to one or the other or both...

What you are telling me is I need to get a new sensor -- right!!!

Yes, if you have this SES code, you most likely need a new sensor...

I had a P0135 code a couple weeks ago on my 2000 fed spec max. But the code is gone now (and I specifically didn't erase it). My problem is that my engine won't go over 4K.

Originally I noticed the problem when the CEL was on. Then it seemed to be fine when the light went off. Then the light came on and the problem was back. Now the light is off but the problem is still there.

I'm thinking of disconnecting the neg battery terminal tonight to reset the ECU then replacing the bank 1 02 sensor tomorrow. I've read posts referring to some sort of safe mode the ECU has so I'm hoping to reset that and correct the problem.

Originally I was thinking that replacing the sensor would fix my problem but now that I'm having the problem w/the CEL off, I'm not so sure.

Does anyone have any other suggestions? If this doesn't work work I'm thinking I might have to take it to the dealership (so you know I'm getting desperate).

Since my last post I reset the ECU and I got the P0135 code about 300 miles later. So I replaced the O2 sensor.

When I first took it out for a test drive it seemed to be running the same. But by the next day it seemed to be running better. I almost picked up a MAF but I decided to give it a little longer and this morning (about 100 miles after replacing the sensor) it was running fine.

So I guess the ECU had to learn new settings based on information from the new 02 sensor? I'm not sure if anyone else noticed a delayed response w/ a new 02 sensor but I'm hoping my problem doesn't come back.

Hey guys,
Wrenching on my cousin's 01. Went to AutoZone for an OBDII scan; code was for O2 sensor bank 1, sensor 2. Is there such a thing? Looking at the first diagram, it appears there is a "front" and "rear" sensor for bank 1.

Which would correspond to "sensor 2"? We picked up a Bosch O2 sensor, but it looks like they gave us a 4-wire when the black harness B1 O2 sensor appears to be a 3-wire.

Any advice? Thanks!

I can only assume that the black harness B1 O2 sensor would be considered "sensor 2" since it is further down the exhaust system?

As I said B1 black front seems to be a 3-wire, and AutoZone gave us a 4-wire O2 sensor. Any and all input is appreciated.
:)

For those of you that have received P0135 - Did your CEL come on during cold conditions?

Is there such a thing as a Bosch 3-wire O2 sensor or am I crazy? As I said, it looks like the 4-wire O2 sensor we have now will not fit the clip of sensor 1, bank 1, front.

http://www.soundoff92.com/bpullen/P0135.jpg

I have fed spec, but found that the 2 on front all have 3 wires while the one of the back (bank 1) have 4 wires.

Ya. I just got a universal one from NAPA (3 wire). I had to cut the connector off the old one and splice it into the new one but it's not that hard with the splicing tools the kit gives you. $65 vs. nearly $100 for the one with a built in connector. CEL (P0135) is now gone and the car feels smoother so I'm happy.

getting the O2 Sensor connector disconnected
 

I pulled on the wires to get the connector off, but it stays put. Is there a release that has to be depressed to get the connector out?
Thanks!
Paul

I used this guide this weekend to fix my P0135... I went with a Bosch Universal heated O2 sensor (3 wire), after tax it also was ~$65. Its working great here.

kind of confused
 

i have a p0135 code. 02 heater circuit bank 1 sensor 1

i'm on www.oxygensensors.com and i don't know which one i have to buy.



From the pic at the begining of this thread ,it seem to be the front pre cat i have to buy. (Walker 250-23121)
Can someone can confirm that to me please.??


thanks in advance

So the 99 maxima only has 2 02 sensors in total ???

NO

the 99 has either 3 total or 4 total, depending on if it was a FED spec or CALI spec maxima.