triax37

iTrader: (1)

Hey everyone - I just replaced my rear upstream O2 sensor (after 90k miles, P2251 popped on), and thought I would do a quick DIY since I didn't see an official one. The difficulty is probably a "2" (scale of 1-5), and would cost $100+ labor from the dealer. It took me about 1 hour. For what it's worth, my freeway mileage increased from 25mpg to 32mpg:

Part: O2 Sensor - 36531-RCA-A02 SENSOR, LAF ($120'ish)
Tools: 10mm, 12mm socket wrench, and O2 socket wrench or large adjustable wrench, arms and hands

Thanks to nfnsquared for help getting my thoughts together and for the service manual scan:
https://acurazine.com/forums/3g-tl-2004-2008-93/how-do-i-replace-front-oxygen-sensors-o2-808497/



Remove strut tower bar
1. Three 12mm bolts on left side and three 12mm bolts on right side.
2. Drivers side - there are two 10mm bolts (blue arrows), and 2 plastic clips holding cables to the strut bar - I didn't take a picture of the clips, but they are pretty easy to see.



3. Passenger side - there is one 10mm bolt (blue arrow) holding the bar down. There is a clip obstructing access to the pictured bolt, so remove this. After you remove the clip and bolt, swivel the part attached to the firewall (red arrow) so that it is out of the way of the strut bar bracket.



4. Now, remove the strut bar. It may require some jiggling - just keep pulling.

Remove the old O2 sensor
5. Find sensor - it's located in Bank 1 of the engine, on the passenger side, between the engine and firewall. You'll see it - trust me. The sensor is pointed towards the ground, with wires pointed in the air.
6. The sensor unscrews with an O2 socket wrench, or (if you're lucky like me) a large adjustable wrench. A socket wrench or adjustable wrench will fit down there, so lean against the passenger fender (cover it with a workmat if you have one), and get your head and arms in there. Some (like me) had better luck with a warm engine, but it's just an option. Lefty-loosey...and once you get some give, don't unscrew it all the way.
7. Now unclip the harness - there are two mounting points, (i) a piggytailed clip facing the engine, and (ii) the standard O2 sensor harness clip facing the cabin. Do the one facing the engine first - push the metal piece away from the harness, towards the engine, and slide off the O2 sensor harness off the piggytailed connection. Now that the harness is free, you can easily unclip the harness. Unscrew the rest of the way, and remove.
* Unfortunately, I spent the most time on this because I didn't realize there were two clips holding it to the car. Once I removed the piggytailed connection, the other one was easy.


Install New O2 Sensor
8. DO NOT TOUCH the new O2 Sensor's head. If you bought a new sensor from Honda, it will have loctite on the threads, but not a bad idea to put some more on there. Hold via handle, and gently insert into engine. Screw / torque down to 33 lb.ft.
9. Connect harness.

Put everything back together
10. Slide back on to piggytailed connection.
11. Replace Strut bar, including ancillary screws and clips.
12. Reset ECU - I unplugged battery, and had my navigation/radio codes handy to get them functioning again.

dwb993

iTrader: (13)

Nice write up...thanks!

Flick

Why just replace the one??? I'm at 134,000 miles and just trying to keep up on things, should I be replacing all of them with my mileage???

triax37

iTrader: (1)

Flick - the simple answer is cost. A new upstream O2 sensor will run you $120 or so. If you're noticing a loss of mileage, the O2 sensors are common causes. If you're still getting 30 mpg at 70 mph, then your sensor is probably working fine.

Keep in mind the computer is always checking the sensors, so if there was a big problem, you would get a Check Engine Light.

Flick

Changed mine out today, was nice and easy from this write up. PITA without an O2 wrench but just cut a 7/8 wrench down and used a pry bar against the fire wall and finally came loose. Thanx triax37

cjTL

iTrader: (2)

Yep. Your car will let you know when its time. My CEL came on in February and it was the O2 sensor. It really improved my fuel economy...I wasn't expecting it to. I averaged about 2MPG better than before.

elproducto

MY P2251 Cel comes on intermittently. When I start the car the light is one sometime and other time it is not on. It think I will check the wiring. Do you think my sensor could be bad?

I hooked up my Code Reader and it read as follows:

02 Bank1 Sensor 1
Negative Current
Circuit/Open

azzyork

where exactly is this from a far angle, a picture would be nice

Jamaken

hey guys,i really need some help,i havea 04 TL and the check engine light came on about 6 weeks ago,the code was P2197,Bank 2 Sensor 1.
I got the sensor replaced and cleared the codes,drove it for 2 weeks and then the check engine light came back on,it was the same code (P2197),the mechanic replaced the sensor and i drove it again for maybe 3 weeks and the light came back on again,i'm not sure what is going on,i know he used a Bosh brand name sensor,it should have been fine.

The dealer is trying to charge me 115 dollars just to run diagnostic check,plus most likely a huge azzz bill for labour,i need help,what could be the problem.

I checked another mechanic and he was telling me that the problem is because i used Bosh and not Denso sensor,i haven't really seen any posts of people having problems with Bosh so i'm scared of buying the Denso and just wasting more money.

Please help.

nfnsquared

Bank 2 is the front bank.

He did replace the top (upstream) sensor on the FRONT bank, correct?

Also, there are a fair amount of bad reviews on Bosch O2 sensors. Search around...

Jamaken

Yes<Bank 2 is rigt up front,it was easily accessible,thanks.how do i find the part number for the o2 sensor in question?

nfnsquared

Use the link in post #1.

Could also be a loose/melted/shorted connection. Be sure you inspect the harness before dropping more $$$$.

triax37

iTrader: (1)

Re: Bosch - after searching around the 3G forum, I didn't find anything conclusive on Bosch/Denso. So I strolled over to the 2G forum, where people definitely had issues with the Bosch sensors. I ended up buying the Honda part.

triax37

iTrader: (1)

Hi - what are you looking for? The last picture was taken from me leaning over the passenger side fender - if you remove the engine covers and lean over, you'll see one set of wires leading to the O2 sensor, pointing towards the ground. Let us know how we can help clarify.

azzyork

got it! thanks alot

csmeance

Added to the 3G Garage/Service Dept! E-130!

jokerman826

I was wondering, I am throwing a P2197. There was a TSB on it. Should I go to the dealer to see if the TSB was sone on my car or just replace the sensor. My concern is that if the ECM update was not done, then the code will just keep showing up. It is not throwing a CEL, I just randomly pull codes on my cars and this one keeps showing up. I think its worth it to just see if the ECM update was done and see if I could get a "goodwill" update done if it wasnt. Any opinions on this? Thanks

Edit: I will be checking the tightness of downpipe and sensor before hand. I read after i wrote this that a bad seal can cause this issue as well.

triax37

iTrader: (1)

If you have time, I would go in. But if you're busy or live far away from a dealer, you could call to get that information. I did that when I bought my 2005 Acura in 12/2010, and they confirmed everything had been done.

jokerman826

I called all three dealers that my car has been to and none of them have any info of it being done. The car i bought it from purged my car out of their system since it hasn't been there in years. I think thats BS, now i have to go get the sensor and maybe not fix the problem or go to acura and see if the ECM was updated and pay $140. Either way, I do not know if the sensor will fix it or if the Update was done and if that will work. Any suggestions?

erdoc48

Hi Everyone,
Sorry to resurrect an old thread, but I just had a P0134 code after a CEL, so I referenced this thread, bought myself both primary O2 sensors (Honda OEM) and replaced them - it's actually pretty easy with the proper tools (as above, and an O2 sensor socket is a must unless you have really small hands). I also checked the torque of the rear bank of spark plugs while I was working without the strut bar in place- they were in nice and tight. I checked the front bank a few months ago. I cleared the codes with my code reader and I'm ready to go. I used dielectric grease in the connectors and used some contact cleaner prior to the grease. I also used O2 sensor safe thread lubricant to avoid galling the threads when installing the sensors and made sure the mating surfaces had no rust for a secure connection.

This is an excellent thread and was extremely helpful!

MEKO

iTrader: (1)

36531-RCA-A02 SENSOR, LAF
36531-RDM-A01 SENSOR, FR. LAF
36532-RKB-004 SENSOR, FR. SECONDARY OXYGEN
36542-RKB-004 SENSOR, RR. SECONDARY OXYGEN

That's OEM but would Bosch work?


15401
Oxygen Sensor Upstream Rear
J32a3 eng.

13965
Oxygen Sensor Upstream Front
J32a3 eng.

13851
Oxygen Sensor Downstream Rear
J32a3 eng.

13853
Oxygen Sensor Downstream Front
For vehicles with automatic transmission
J32a3 eng.

15471
Oxygen Sensor Downstream Front
For vehicles with manual transmission
J32a3 eng.

15730
Universal Oxygen Sensor Downstream Front
For vehicles with manual transmission
J32a3 eng.


--------








Comes to $341

Edit: Posted 4 links, don't know why there is 7 amazon links

I hate cars

I'm getting ready to do mine and I plan to do both obviously, but I'm looking for Denso. It may not apply to the TL but in my past experiences with Denso 02 sensors, they stand up to the extreme heat of my turbo car and leaded race gas far better than anything else including Bosch.

Is the stock sensor Denso by chance?

jimmriley

Appreciate this post very much. I have a 2004 tl manual trans. I am wondering if I could follow this same procedure to get to the bank 1 upstream O2 sensor (check engine light code of 2551). This post seems to be for a different O2 sensor. I am not even sure exactly where the bank 1 sensor is other than it is before the catylitic convertor.

triax37

iTrader: (1)

Jim - this post is to fix the code 2251. The O2 sensor is located on the passenger side of the car, in the back of the engine closest to the firewall. If you are standing over the passenger front tire, look to the left of the power steering pump and shine a flashlight down into the back of the engine. You'll see the O2 sensor - it's pointing straight up to the sky. Let us know how we can help.

Wh1t3r0b

hi guys! i just wanted to say thanks for this thread. I have a '05 RL that was throwing p2237 and sometimes p0134 codes. Replaced the sensor and no codes have come back! Same process for anyone wondering!

triax37

iTrader: (1)

Glad to hear it! There's so much repair/maintenance information I've learned from AZ (and the Nissan Maxima forums, my previous car), so I'm happy to have contributed a very small amount!

TriCity330

Excellent post & pics. O2 sensor came out/went in just as described. Thanks!

Deust206

Hey guys I'm new to this website and jus became a member. I have a issue with my 99 Acura TL and I was hoping someone could give me some insight. My car would start and die sometimes and when I start it I would have to rev the engine a couple time before driving it and drive right away... That went on for some weeks cause I didn't have the money to fix it at the time.. And now it stops excelling when i drive it and when I pulled over on the side of the road it totally shuts down... I replace the cat converter but not the 02 sensor ... I don't want to keep replacing stuff and them not be the problem.. I need help someone ???

Deust206

Hey guys, I'm having a problem with my 99 Acura TL, sometimes when I start it up it dies and I have to rev the engine a couple of time to keep it going and immediately put it into drive, that went on for weeks cause I didn't have the money to get it diagnosed. Now when I'm driving around town or on the freeway it stops excelling and slowly comes to a stop but before it stops it dies completely... I replaced the cat converter and it is still having the problems. I'm not a car guy and I'm not sure what the issue is... Is there anyone out there that could give me some insight ???

bla8291

It would certainly be nice to have a writeup for the front oxygen sensor as well. I've searched high and low on this forum and I haven't found anything. I've got codes p2254/p0154 to fix.

triax37

iTrader: (1)

Thanks for your post. This group is focused on the 2004-2008 Acura TL, so please post your question in the 1999-2003 Acura forum. While the engines are very similar and someone here could help you, I bet you might have better luck with people who's cars are similar in age as yours.

Sounds like an opportunity for YOU to create a write-up. Good luck!

bla8291

It would be, if I knew what I was doing. I don't, which is why I was looking for instructions.

errrrr1

I just wanted to Thank You for this post! I just replace my O2 and NO more check engine light! Cheers!

triax37

iTrader: (1)

You're welcome!

Acura7880

Hi i ve been reading this thread and have found it very helpful, i received these two codes P0134 and P2237 and replaced the bank one sensor 1 sensor (which is located almost right in front of you when you open the hood behind the radiator connected to the cat) and it cleared out the po134 code, however im still getting the P2237 code, i looked this up and read it was the A/F sensor, i purchased this sensor and a bit unsure of the location of this part, im assuming its shown in the pics under the strut bar but i wanted to make sure before i start out,thanks for all the help

triax37

iTrader: (1)

Sorry - I don't know anything about the A/F sensor, but hopefully someone else does. I found this thread which has some information on P2237:

https://acurazine.com/forums/3g-tl-problems-fixes-114/05-acura-tl-p2237-p0134-811242/

DwhiteReApEr

Great write up. Im about to replace my O2 Sensor as well (@ 170k miles its a little overdue). I know there are two, one front and one rear. Do both need to be replaced, or just the rear. And I also wanted to ask about the Wideband O2 Sensor, is it worth spending the extra money to get that? Thanks in advance for the Help.

rich_1017

Ok, took a while to understand what exactly the picture was showing but there is a tab on the plastic gray connector which is attached to the metal pigtail tab. Pull the plastic connector tab towards the engine & it will release the plastic connector from the metal tab. Once the 2 plastic connectors are released from the metal pigtail they can be pulled apart.

ATLS_666

WhAt a cunt the clip is to take off...still at it. Tugging the clip toward the engine and sweet fuck all is happening.

ATLS_666

Finally for fuck sakes.