Oxygen Sensor (Rear) changed for 2.4L I4

[sean20202020]

I changed the rear oxygen sensor.


Why? I got check engine lights 5 times for 3 months.
The 2 OBD codes were
- P0138 (O2 Sensor Circuit High voltage Bank1 Sensor2)
- P0606 (ECU/PCM Fault)

First I changed the 4.5 years old battery hoping the ECU became crazy because of
low battery voltage when cranking.
3 weeks later, the same 2 codes were returned.
So now O2 sensor changing is my next try.



Model: Toyota 2006 Rav4 Base, odo 50,000 km
Engine: I4 2.4L 2AZ-FE

Sensor: Heated Oxygen sensor (After catalyst or Rear) Bank 1 Sensor 2
- OEM Toyota : TOYOTA 89465-42170
- Replace: Denso 234-4209 (Universal type, Splicing needed) Amazon.com $45 (Shipping $15 to Canada)
or 234-4622 (OE fit plug included, just plug in, no splicing) $60~$80 + shipping



0. Preparation & Observation
1. Take out old sensor
2. Prepare new sensor
3. Install New sensor

Today I received rear O2 sensor package.
Good packing and brand new Denso part.
includes
splicing metal crimps,
heat shrink tubes
& anti-seize compound.




Rav4 I4 2.4 has 2 Oxygen sensors, Bank1 Sensor1 and Sensor2.
I am changing only Sensor2.
Find the same type plug under hood and practice unplugging with a flat screw driver.




Sensor1 is located at just left side of the Battery.(I don't change Sensor 1)

Again, Find the same type plug under hood and practice unpluging with a flat screw driver.




ADDED PIC: I added this picture to show the same type plug.





Before go under body,
Let's try to find the Sensor2 from engine hood's left top view.
You can see just cable of the sensor.



Look at deeper inside
Now we see the sensor, cable and plug.







Time to crawl under...
I used 2 ramps & rear wheel chocks.
Also I added 2 extra stands under stand points,
you never know what will happen to the ramps.
I don't want to be found under the Rav4.




Sensor2 is located at about 20 cm backward of the engine oil pan plug under body.




Where the cable is going?




Oh there is the sensor plug.
I had to use 2 hands,
left hand for pulling out the cable, right hand to put a flat screw driver into the side of the plug.
After 30 seconds screw driver try, it's disconnected.

PRACTICE WITH THE SAME PLUG ON THE ENGINE (see 2nd & 3rd picture)



Now I splayed PB blaster around the sensor. and wait 10 minutes.



22 mm (7/8 inch) wrench... Open-end of the wrench must fit the sensor.
With this small Rav4 plug,
I could put the box-end wrench thru the plug, better than open-end.



Turn counter-clock wise.
I used only about 30% of my one hand mustle. PB Blaster made it easier? Probably.



Got it out. this old sensor part number "TOYOTA 89465-42170"



I will cut the OEM old sensor cable to re-use the plug.



Old OEM sensor has different cable colors from new Denso sensor;

DENSO -------- OEM MEANING
=============================================
BLUE ------- BLACK Signal +
WHITE ------- GRAY Signal -
BLACK ------- WHITE Heater
BLACK ------- WHITE Heater

I used a soldering iron to connect it,
but I realized the cable's metal wire was not really friendly to the solder lead,
lead does not well stick to the wire.



So instead of the lead soldering,
next time I will just use the included metal splicing crimps.



Anyway I managed to use soldering.
Heat shrink tubes on the connection, my heat gun make them tight.
(If you don't have a heat gun, just use a cigarette lighter)
Also I used electric black tape on top of them.



Before put the new sensor into the bung,
I put the included anti-seize compound on the bolt thread.



My hand put the sensor in.
then I used the box-end wrench with the little finger of my right hand.
Then, put the electric plug in. Job Done!







Used part;
Denso 234-4209 Universal type, Heated oxygen sensor
I bought thru Amazon.com seller $45 (Ship $15 to Canada) Total US$60 paid.

Denso 234-4209 Universal
http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2FDenso-234-4209-Universal-Oxygen-Sensor%2Fdp%2FB000C5WCUE%2Fref%3Dsr_1_1%3Fie%3DUTF8%26s%3Dautomotive%26qid%3D1288234255%26sr%3D8-1&tag=5336653677-20&linkCode=ur2&camp=1789&creative=9325
Denso 234-4622 OEM fit
http://www.amazon.com/gp/redirect.html?ie=UTF8&location=http%3A%2F%2Fwww.amazon.com%2FDenso-234-4622-Oxygen-Sensor-Ratio%2Fdp%2FB000C5SGA4%2Fref%3Dsr_1_1%3Fs%3Dautomotive%26ie%3DUTF8%26qid%3D1288234542%26sr%3D1-1&tag=5336653677-20&linkCode=ur2&camp=1789&creative=9325



Used tools;
- Ramps, stands, chocks
- PB blaster ( $8 )
- Flat screw driver
- 22mm (or 7/8 inch) wrench
- Cutters or pliers
- Heat gun or cigarette lighter
- Electric tape
- Soldering iron & lead (optional, Just use the included splicing metal crimps)
- Anti-seize compound (included)







Time to do;
- About 1 hour to be careful, If I do again, now I can do within 20~30 minutes.




Disclaimer:
This is just for EDUCATIONAL ONLY information.
I do NOT recommend or ask you to do the same.
I am not responsible for anything you do ever, regarding your vehicle or anything else. Anything you choose to do, you do of your own free will. I cannot be held accountable for anything you try. I am not a mechanic or a technician. I have no official knowledge of anything regarding Rav4, but am simply relating my own experiences. DO EVERYTHING AT YOUR OWN RISK. ANYTHING YOU DO MAY VOID YOUR WARRANTY OR RUIN YOUR TRUCK. Death or injury, serious or otherwise may occur if you try anything on this page. YOU HAVE BEEN WARNED.

Edited for P0168 (typo)--> P0138 (right code)

[Mikey D.]

Excellent post sean20202020, very explicit instructions/photos! Thank you for taking the time to explain/illustrate this 'fix'.

I am glad that you chose to solder the wires and not use the supplied crimps when you spliced the plug wires to the sensor wires. The soldering job that you did was both mechanically and electrically sound! I would have done exactly as you did (solder) and I would recommend that it be done that way (solder) as well! It might take a little longer, but the splice should last until you have to replace the sensor unit again.

Mike

[Carbon]

Originally Posted by Mikey D.

Excellent post sean20202020, very explicit instructions/photos!

That was pretty explicit for a stick figure.

Exceptionally good write-up.

[revhigh]

Excellent post. The only thing I would add (and I'm not sure about this), is that most times that plug can be disassembled, and the new wires can be wired properly to the plug itself. As I said ... I'm not sure in this case ... it may be sealed permanently, in which case, the only way to go would be the way the OP mentions or the crimps, both of which will work satisfactorily.

Great write up and pics !

REV

[ricepower]

Excellent writeup!!! Even an infant can do the rig!

[RAV4Don]

Great write up!

One bit of advice I would offer to those considering replacing an O2 sensor is to get a specific O2 sensor for your application and not a universal fit one. You will probably pay more but O2 sensors are critical engine control components and they reside in a harsh environment. I would avoid cutting and splicing the O2 wiring if possible.

[RF Overlord]

Great write-up sean...thanks for taking the extra time to get good pix.

In future, to be politically correct, you should make your stick figures bi-sexual...no, wait...unisex...or is it asexual?

Just a general word of caution: some factory O2 sensors (Ford for example) have a shielded cable for the signal leads, so splicing is not recommended.

[earthrealm]

excellent post!!.am having the same problem on my 2003 rav 4wd..since evryone is against the splicing...cud some1 direct me to a site where i can buy the oem type in the US?
mine has error codes p161 and p141

[sean20202020]

Originally Posted by earthrealm

excellent post!!.am having the same problem on my 2003 RAV 4wd..since evryone is against the splicing...cud some1 direct me to a site where i can buy the oem type in the US?
mine has error codes p161 and p141

1. I don't know if the part is also for your "2003" I4 engine.
2. Also, you have to check if your sensor is easily accessible with the open-end wrench.
Otherwise, you might need a special o2 sensor wrench. so find your existing sensor and check if out.


If 1 & 2 are all confirmed for 2003 rav4,

In my original post up there;

Used part;
Denso 234-4209 Universal type, Heated oxygen sensor
I bought thru Amazon.com seller $45 (Ship $15 to Canada) Total US$60 paid.

Denso 234-4209 Universal
Link

Denso 234-4622 OEM fit
Link

<===== The second sensor,Denso 234-4622, has a plug already. http://www.amazon.com/Denso-234-4622...8234542&sr=1-1


By the way, I have 20+ years' experience of the soldering.
also I enjoy soldering and saving.

However if you have no idea about electric wire, just buy OEM fit with a plug.
In Amazon USA, only $68 with free shipping.

Thank you all.

[earthrealm]

ok thanks for ur detailed help......will try out the sites