DIY Tundra O2 Sensor #1 Replacement

[ericb]

Moderator: Please consider for a sticky thread.

I recently got a Check Engine light with a code P0051 which an internet search described as a Bank 2 (passenger side), sensor #1 (exhaust manifold) oxygen sensor failure. P0031 would have been the driver side.
I ordered a new Denso sensor from an internet site for about $115 plus shipping, plus a short 22mm sensor socket, and bought a can of PB blaster from a local parts store.
I put the front wheels on ramps, crawled underneath and ran into a show stopper: I couldn't disconnect the electric connector because it seemed to require 2 hands in a place where there was barely room for one. A question on this forum gave me the answer. Here is the replacement procedure:

1: Get a replacement Denso sensor (they make the OEM part), a 22mm sensor socket (the low profile one works best), PB blaster.
2: Put the front wheels on ramps, blocks. Put truck in park, set the hand brake, use jack stands if you're not using a ramp.
3: From underneath the truck, locate the sensor at the back of the exhaust manifold, spray liberally with PB Blaster, and follow the wires to the electric connector on the engine block.
4: Usually, you press on the release tab on the back of the female socket (the part fastened to the engine block) and pull the male connector out with the other hand. There is not room for two hands and the release tab is too difficult to reach. The solution is use a medium to small screw driver, place it inside the connection so that it raises the release tab. The tension should hold it in place while you grab the wires below the connection and pull gently. The connection should come apart. If not, try a slightly thicker screw driver to lift the tab more and wiggle the wires back and forth as you pull. It really doesn't take a lot of effort.
5: If you don't have a code reader to clear the code with, disconnect the negative battery terminal so the ECU will reset and clear the code.
6: After the PB Blaster has soaked in for about an hour, start the engine and let it run for a minute to warm the manifold and sensor.
7: Use the sensor socket (slotted for the wires to fit through) to remove the old sensor. Be careful when it comes out as it will be hot.
8: The new sensor should have come with anti-seize (if not, get some). Spread liberally on the threads, hand thread into the manifold, use the sensor socket to snug it down, and reconnect to the female socket. Tug gently to ensure connector has snapped into place.
9: Use a code reader to clear the code and take it for a test drive.

[Cian]

Thanks for that. I need to do this for the driver's side (bank 1 sensor 1).

I tried earlier today, but what a PITA!!!

There is absolutely no room to get two hands in there, but from what I've read it seems that is the norm.

Unfortunately, I can't get a decent shot at the socket with the PB plaster since it's partially blocked by the manifold coupling.

I'll try again tomorrow. Maybe I'll invest in a pair of ramps.

[reb101]

I just used a friends code reader... I got the P0135 bank 1 sensor 1 o2 sensor heater circuit malfunction. I have never tried repairing it myself... seems like a lot of trouble. But, I just replaced an o2 sensor... guessing it was the rear one?
I went years without this crap... now they fail all the time...
I had a dealer strip the threads on my headers years ago while replacing an o2 sensor... just a little frighten about trying it myself now... hehe

Any chance I can do this? I don't have blocks. Was going to go to auto-zone and rent the tool. Would hate to take it apart and not be able to put it back together...

If anyone could suggest where I could get a good price on the part and maybe a diagram of the location of o2 on my 2001 tundra v-8... would be greatly appreciated... I blew $300 at the dealer last time/ that hurt!
I was in and out in 20mins. though; guess that's the least they can do for screwing us.

PS) i made note of the PB Blaster spray and anti seize needed... not familiar with that though.

[coolstuff]

thanks for putting this up there - I am off to try using a small flathead screwdriver to get this outta the wiring harness thingy

later

[coolstuff]

man - this thing is a pain - do I jam that screwdriver up in there real hard?

ugh - this is frustrating

[Tones]

I believe bank 1 sensor 1 is the driver's side front sensor. The front sensors are the one's that seem to go out the most. Ramps are not necessary but it is a pain to do. When removing the sensor, the threads seem to gall a lot with carbon. Just work the sensor in and out while spraying with WD40 or PBBlaster. Be careful because when laying under the truck your head is directly below where you will be working. Wear your goggles for this one. I rented the AutoZone tool and it worked very well. Rock Auto had the best price on the sensor when I was looking.

[Mike-buh]

This and other forums have been incredibly helpful. I just finished replacing both front sensors and have only this to add to all the great advice:
To unclip the electrical connectors I found the screw driver trick too hard, and by hand it went easy - but you have to be on your back with your feet facing forward to be in position for this. For the passenger side clip, you press on the release tab with your index finger while flexing your pinky against the wires... it puts enough tension on the cable to pull the connector out. Curse and wail as needed.
To loosen the sensors themselves I could not get leverage from the same position - you have to be on your back with your feet facing back for this to work. Curse and wail as needed, as always.

Carma Sutra!

[pinnacle]

I'm getting ready to do this on my 03 Tundra. I also have the P0051 error code (passenger side, exhaust manifold). I went to the Denso web site to check on the part and it appears that 2WD Tundras have two oxygen sensors (one front, one rear) and 4WD Tundras have four oxygen sensors (two front, two rear). Am I understanding this correctly? I have not got under the truck yet. I called the local Toyota dealer but the parts guy could not say for sure. This is where I am looking:

DENSO Aftermarket: Catalog Search From DENSO: Quality Aftermarket Automotive Parts

Thanks.

[pinnacle]

Thanks to everyone that posted about how to fix an P0051 error code for the front passenger side oxygen sensor. Thanks to everyone else, my experience went very well today. I would like to add the following.

First, as others have said in this post and others, getting a special socket for this job is a must. I found one at Harbor Freight dirt cheap but ended up going with this OEM 27110 set on amazon instead for $17.24. I did not know if I would need more than just the socket but I wanted to be prepared for anything. As it turns out, I only used the socket.

Amazon.com: OEM 27110 Oxygen Sensor Socket: Automotive

Also, I bought an Equus 3030 engine code reader for $59.99. This was optional since in most states Advanced Auto will read your code for free but I figured with all the money I was saving by not having this problem fixed at the dealership, I could splurge and buy another tool. I love tools. Before I started the project, I used this to confirm that I only had one bad sensor. It had been awhile since I had Advanced Auto read my code so I wondered if a second one had gone bad. So far, only the front passenger side ox sensor has gone bad. From what I read on the Internet, most of these low priced engine code readers have the same features. I picked this one because the display was bigger than the alternatives.

Amazon.com: OEM 27110 Oxygen Sensor Socket: Automotive

Lastly, I bought the new oxygen sensor. I called the dealership and they wanted around $157 if I remember correctly. Next, I checked Rock Auto. I found an exact replacement Denso (OEM not universal fit) for $62.01 after my discount including shipping. I discovered on Coupon codes and discounts for 30,000 online stores! RetailMeNot.com, a promo code that I used for an additional discount in order to get the price that low.

Finally, it was time to actually get under the truck. After 94,000 miles and numerous Michigan winters on my '03, I was expecting a long day. Thankfully, I was wrong. I tried to take plenty of pictures as I went to help out the next person to read this thread. Here's an overview of the sensor. I found it was often easiest to get to it with my body parallel to the body of the truck with my feet under the front bumper.



Below is a closeup of the threaded portion of the sensor. Most of my time was spent removing this. The rust had seized it up. Unfortunately, I had not sprayed it with Liquid Wrench prior to today. You will need some exensions for your ratchet in order to get at it. I did not have a really long extension so I combined two 6" extensions. It was not budging so I encouraged it a little with a cheater bar. I tried to be patient because I had read on the Internet about people stripping the threads. Eventually, it broke loose.



Here's the threaded portion after removal.



As many other people have noted, getting the plug end removed can be a real pain. First, I tried the screwdriver method to try to unclip it. This was going very badly. I was concerned that I was going to break the part that remains on the truck for the next sensor. Then, I reread this thread again. I tried to use my middle finger to reach up on the top side of the plug, release the catch, and then use my remaining fingers on the same hand to remove the plug. It is only possible to get one hand up there at a time. In order to do this, I had to work blindly with my feet under the front bumper. Amazingly, despite my big hands, this worked very easily. Here's a closeup of the plug end of the sensor.



And here it is again after the plug was removed.



Installing the new one was easy. The Denso replacement came packaged with some anti-seize. There was plenty left over for future projects too. Here's the finished install.



Lastly, I used my new engine code reader to erase the error. I put the truck back down on the ground, started it up, and for the first time in months there was no engine light on.

Thanks again everyone for making this project go so well.

[FreeMonomoy]

Thanks for the great helpful posts above (and the photos). I had a P0031 code and tackled my front drivers side O2 sensor on my '03 Tundra yesterday. From start to finish, the job took me 18 minutes. I'm no 'check engine' light free. Total cost for the job was $80. $20 for the O2 sensor socket kit and $60 for the OEM Denso Sensor.
Thanks.