# Front O2 Sensor Installation



## jonnydanger (Apr 6, 2007)

I recently had my 97 2.4L 4x4 pickup at a Nissan dealer because the engine light was on. Turns out it was throwing the "Fuel Mixture Too Lean" code. The dealer tested a few things and found a bad front O2 sensor. They charged me $245 for a new one (pissed to find it on the net for $85 later that day). 

So..... I am trying to save some money and am thinking about installing the O2 sensor myself. I have read the service manual and it looks as if it's as easy as tighening a bold. The dealer STRONGLY advised me to let them do the work but i'd prefer not to throw more money away...

Is there anything specific I should now about installing the O2 sensor that maybe only the dealer would know how to do?

Thanks!


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## spat (Oct 15, 2005)

jonnydanger said:


> I recently had my 97 2.4L 4x4 pickup at a Nissan dealer because the engine light was on. Turns out it was throwing the "Fuel Mixture Too Lean" code. The dealer tested a few things and found a bad front O2 sensor. They charged me $245 for a new one (pissed to find it on the net for $85 later that day).
> 
> So..... I am trying to save some money and am thinking about installing the O2 sensor myself. I have read the service manual and it looks as if it's as easy as tighening a bold. The dealer STRONGLY advised me to let them do the work but i'd prefer not to throw more money away...
> 
> ...


Have you checked the TSBs? Also please clarify, I am assuming this is a second time the same sensor has failed. How long ago was this same sensor replaced? What is your current mileage? Was the $245 for the sensor only or the complete repair? Aside from knowing a few things to watch for it is not usually a difficult task. Plus it is best to use an O2 sensor socket tool ($30). OEM parts are almost always more expensive but usually more reliable. If you use the vehicle off road a lot or live in an area where there is a lot of salt exposure you may encounter some corrosion issues that will hinder the replacement task. If you do the work yourself be very careful when removing the air cleaner housing, the MAFS is an integral part of the throttle body. If any debris fell down into the MAFS it could damage it. The MAFS will cost several hundred dollars to replace if it where to get damaged.


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## smj999smj (Jan 1, 2006)

Don't overtighten it...other than that it's pretty cut and dry.


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## jonnydanger (Apr 6, 2007)

The truck has 198,000 kms. I have only had the truck since January and this is the first time I have had to replace the O2 sensor. The $245 is just for the part, does not include the installation, the dealer also quoted $800 for a new MAF if it turns out that I need one. 

It looks to me that the front O2 sensor is in the exaust manifold, why would I need to remove the air cleaner housing?

Where can I find the TSBs ?


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## smj999smj (Jan 1, 2006)

I don't recall any TSB's for 97 Hbody front O2 sensor codes nor do you have to remove the air cleaner.

The front O2 sensor is P/N: 22690-5E401 and MSRP's for $140.87. You can pick one up online for about $101; check out Discounted Nissan Parts 

The MAF, actually a "hot wire modulator," should be under $300. They don't list it at the site for a 4 cyl.; you would have to call them. 

What bother's me is the phrase, "the dealer also quoted $800 for a new MAF if it turns out that I need one. " That sounds like they're guessing what the problem is. Determining whether it's the O2 sensor or hot wire modulator, or something else, is causing the "lean" condition is part of the diagnosis. If they charged you a diagnostic fee, they should be able to tell you which one is defective. If they tell you, "Well, it's this but maybe also that..." then they either didn't do the diagnostic testing or the "technician" doing the testing doesn't know what he's doing or just doesn't have faith in his own abilities to do the test. You'd be best just as well to flip a coin and hope that whatever you install fixes the problem.


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## jonnydanger (Apr 6, 2007)

Thanks very much for the info. You pointed out the exact reason why this situation is making me angry. I already paid $70 for a diagnostic test and I don't want to pay the dealer top dollar for guess work. Since I already bought the O2 sensor, I'm going to install it and see what happens. If I still have a problem, I'll have a look at the hot wire modulator.

I may also look into figuring out a way to read the codes myself so I can avoid the dealer all together.


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## spat (Oct 15, 2005)

jonnydanger said:


> The truck has 198,000 kms. I have only had the truck since January and this is the first time I have had to replace the O2 sensor. The $245 is just for the part, does not include the installation, the dealer also quoted $800 for a new MAF if it turns out that I need one.
> 
> _$245 for the sensor only does sound high but we must remember costs on many things have been skyrocketing over the last 3 years do to increased energy costs and it takes energy to produce a ship products, espetialy products that contain valuable elements. $800 for the MAF sensor is probably the same issue but you should also understand that it is an integreal part of the throttle body. I believe it is removable from the throttle body but as far as buying it from Nissan it only comes with the throttle body not separate._
> 
> ...


_TSB info is one of the stickys near the top of the general forum for Truck & SUV
but smj999smj mentioned there is not any on the O2 sensors for your truck. I think he is a trustworthy source. In the future it is usually a good place to start before you start a diagnosis that is not obvious. It truly sucks to spend hours diagnosing a problem when all the info is right at your finger tips, Unless you just enjoy the challenge or want to improve your diagnostic skills.
_

I agree with smj999smj. Whats with the quote for the MAF sensor? Did they give you a copy of the diagnostic code scan? You should always ask for it! I would like to know exactly wich code you have. I was under the impression they tested the O2 sensor and it was found to be bad. Sounds fishy to me if they can't give you a definite answer.


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## smj999smj (Jan 1, 2006)

jonnydanger said:


> Thanks very much for the info. You pointed out the exact reason why this situation is making me angry. I already paid $70 for a diagnostic test and I don't want to pay the dealer top dollar for guess work. Since I already bought the O2 sensor, I'm going to install it and see what happens. If I still have a problem, I'll have a look at the hot wire modulator.
> 
> I may also look into figuring out a way to read the codes myself so I can avoid the dealer all together.


Why not pick up a cheap OBD II code reader? All 96 and newer vehicles in the US are OBD II compliant by federal law. Even though I have access to a scantool, I also have a cheap OBD II code reader/eraser that I picked up at Wal-mart for $68. It comes with a book and CD with code description information. Spend a little more and you can get one with freeze frame info. A little more and you can get one with some basic datastream info. You can also get the codes manually at the ECM, but the code reader makes it a lot easier.


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## jonnydanger (Apr 6, 2007)

Thanks again for the tips... I will try to pickup a cheap code reader for sure...


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## sharpeusn (May 9, 2007)

Yeah the tool for it is a 22mm O2 sensor socket (just has a slit down the side) and use a breaker bar to get the sensor off. Installing is just opposite... Tool 9.99 at autozone, O2 sensor 65.99 at autozone, telling the dealer to kiss your A** PRICELESS.


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## jonnydanger (Apr 6, 2007)

hahahaha that is funny...

I just installed a new air filter (K&N) and the engine light turned itself off. I still have the O2 sensor but have yet to install it, I may just wait and see if the engine light stays off.


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## sharpeusn (May 9, 2007)

Yeah it may stay off for a bit but as soon as you stress out the engine like on the highway or something it will come on again. I had the same issue. I replaced mine but the light is still on but I also have 517,000 miles on the truck too. May be something else how did the filter look?


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## jonnydanger (Apr 6, 2007)

So after driving for a bit the engine light did come back on again (as you predicted). I installed the O2 sensor, and the engine ligth remains on. Do I need to reset the computer after the install, or should it automatically detect that the problem has been fixed?

Also, thanks for the tip about buying the O2 sensor socket, saved lots of messing around with it...


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## smj999smj (Jan 1, 2006)

Disconnecting the battery for a few minutes might turn the light off, but would not initially reset the code in the ECM. Most parts stores have OBD II code readers that will allow one of their employees to clear the code. Otherwise, if you continue to drive it, it will eventually turn off if the problem is fixed, but it might take a while.


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## jonnydanger (Apr 6, 2007)

Ok, so it's standard practice to clear the code after you install a new sensor?


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