Oxygen Sensor Hassle

[ronbo1313]

Bought the 04 in 12-06 and every month for a day the CEL and VSC/no trac light would go on , then turn off in a day. Thought it was dirt on the sensor for the VSC.
Recently found out that the VSC/NO TRAC light comes on from the ECM so I put my code reader on it and got P2238. O2 Sensor 1 bank 1.

Got a DENSO from e-bay for $85 great price since this is an upstream and the pricey one.

Looked thru my HAYNES, then CHILTON online thru my library and the manual for the 2005 RAV4 PDF from this site.

Looks like a total of 4 ea O2 sensor and the one I need to replace is under the heat shield of the front exhaust.

Waiting for my order of KROIL penetrant to begin the removal.

Had to use my 97 CAMRY factory repair manual to get a torque spec for the O2 sensor of 32 ft. lbs. NONE of the mentioned manuals had it or did an web search.

[ronbo1313]

The manual claims my engine( 2004, 2.4l, built in 7-03) has 4 O2 sensors, yet I only see two. One in exhaust manifold and one in exhaust pipe under the vehicle.
Tried to take exhaust heat shield off and because of O2 sensor sticking out , can't remove.

Ran out out daylight today, will work on tomorrow.

Glad I bought the thumb socket ratchets at Harbor Freight, the helped me remove the manifold heat shield bolts.

[ronbo1313]

It's in.
Only a total of two sensor in this vehicle not 4 as the manual claims.
Also , tried to use a deep O2 socket thru the heat shield and NO GO. Removed the heat shield and easy bolt removal BUT a major pain to remove.
Then with the heat shield to the side tried another O2 socket I had and NO GO.
Used an 7/8" open end wrench since the length fitted better than the 22mm I had. Another pain to remove the O2 sensor. It loosen quickly at first which surprised me, it might have been the KROIL I soaked it with overnight and this morning.
Moved the wrench a few mm at a time due to a tight working area. A stubby wrench would have been handy.

Putting the sensor in was was OK. The hard part again was the heat shield.

LOOKING BACK: A stud that was sticking up that a nut attaches to hold the heat shield. It has a star torque shape on top. I bet it was there to attach a socket to and move the stud down and out of the way for the shield removal. Not sure if I have such a socket.

[MNRAV4]

yup, a 7/8ths works much better than the 22mm
you just have to be patient with the tight working area
$85 is a great price, the best I could find was $125 when I did mine

[Keninblaine]

I just found this thread while searching for info related to my 01 RAV4. CEL came on a few weeks ago, and when diagnosed yesterday by local indy shop, found the heater circuit for Bank1 Sensor 2 oxygen sensor is faulty. I was quoted $177 for part and $226 for labor, which I declined. Sensor itself is functioning, but the faulty heater circuit throws the CEL code (P0141).

Am thinking of doing this myself. Anyone know the part number? I found a Denso 234-4209 on Amazon for $38. Just want to be sure it is the right one.

[ronbo1313]

Originally Posted by Keninblaine

I just found this thread while searching for info related to my 01 RAV4. CEL came on a few weeks ago, and when diagnosed yesterday by local indy shop, found the heater circuit for Bank1 Sensor 2 oxygen sensor is faulty. I was quoted $177 for part and $226 for labor, which I declined. Sensor itself is functioning, but the faulty heater circuit throws the CEL code (P0141).

Am thinking of doing this myself. Anyone know the part number? I found a Denso 234-4209 on Amazon for $38. Just want to be sure it is the right one.

Checked your DENSO on Amazon. You have the "universal" which means you have to use the wiring/plug from your old sensor. You must splice the old harness to the new. You might find some videos on youtube on how to do it. Probably not RAV specific. Also read the comments on the Amazon sensor page.

You gave no indication of the year of your RAV. I believe the sensor you quote is in the exhaust pipe under the vehicle. I would spray it with a penetrant for a few days before I attempted to remove it.

[Keninblaine]

Originally Posted by ronbo1313

Checked your DENSO on Amazon. You have the "universal" which means you have to use the wiring/plug from your old sensor. You must splice the old harness to the new. You might find some videos on youtube on how to do it. Probably not RAV specific. Also read the comments on the Amazon sensor page.

You gave no indication of the year of your RAV. I believe the sensor you quote is in the exhaust pipe under the vehicle. I would spray it with a penetrant for a few days before I attempted to remove it.

Thanks for the quick feedback. You may have missed the "01" in front of my RAV4 reference. Checking the TSB it appears Bank 1 sensor 2 is located at the bottom of the heat shield on driver's side. While splicing wires isn't a problem for me, I think I'll opt for the Denso 234-4048 for another $35 as it comes connectorized and ready to go for $67. I'll take your advice and feed it some penetrant while awaiting delivery. The location isn't ideal, but hope I can get in there without any special tools other than a 7/8 box end wrench.

[Keninblaine]

Update: I ordered the Denso 234-4048 and it is in transit for delivery on Thursday. On the weekend I picked up the O2 removal tool from Harbor Freight for $7.00. Yesterday I removed the plastic shroud under the motor on passenger side and tried the tool on the lower sensor. This sensor is probably the least accessible one of the four, yet I was able to use the tool to loosen the sensor. So there is no need for liquid wrench treatment. I expect the shop removed the sensor last week when doing the diagnosis.
So the total cost of this job is going to be about $75 vs the $451 (incl tax) quoted by the shop.
I also picked up an Autotel OBDII scanner for under $20 to save the $148 diagnostic charge next time I get a CEL.

It never ceases to amaze me how much useful information there is on the internet if you take the time to look for it.

[Neil22]

rockauto.com is a good reference for finding part numbers for just about any car. I use it for all of my cars. Then usually I'll just buy it from Amazon since I have Prime.

[Keninblaine]

Originally Posted by Neil22

rockauto.com is a good reference for finding part numbers for just about any car. I use it for all of my cars. Then usually I'll just buy it from Amazon since I have Prime.

Thanks for that lead. Their prices are very good!