[Keelaboosa]

It took me a long time to sift thru the search results to find a comprehensive list of parts, tools, and supplies I needed to change out my O2 sensor. Rather than add to one of the myriad threads on the subject, I'd rather start another one. This way all the useful information is at the top. If you found this thread as a result of a search, I hope you find the information helpful.

[size=+2]Amazon sells our O2 sensors, Tools, & Supplies[/size]​

Our cars come with three O2 sensors. Each of the two pre-cats has a sensor associated with it located above the precat. These two sensors are identical, and are called the "upstream" sensors. The third sensor is located farther down the exhaust near the main cat. This one is called the "downstream" sensor and has a longer harness than the other two.

Question 1 - Bosch or Denso?
Forum wisdom points us to Denso instead of Bosch. I won't get in to which is better and why, but you can click here for a search on the subject.

Question 2 - OEM or Universal?
You can get OEM (original equipment manufacturer) sensors that come with connectors and the correct cable length. They cost more than universal sensors, but they're easier to install. The only difference is OEM sensors come with a connector and two different harness lengths, depending on if it's upstream or downstream. If you're comfortable cutting and splicing wires, and you can cut the connector off the O2 sensors you're replacing, then use the universal sensors. They're functionally identical to OEM sensors, they're much cheaper, but they do require some fiddling.

Below are links to the 2 OEM sensors you need if you don't want to splice, as well as a link to the Universal sensor if you're prepared to tackle this project. Seriously, it's not hard.

IF YOU DON'T WANT TO SPLICE

Denso 234-4624 Oxygen Sensor (Air and Fuel Ratio Sensor)
Approx. $60. This is the OEM Upstream O2 sensor that goes before the precats. You need 2 of these.

Denso 234-4603 Oxygen Sensor (Air and Fuel Ratio Sensor)
Approx. $65. This is the OEM Downstream O2 sensor that goes after the precats. You only need 1 of these.​

IF YOU DON'T MIND SPLICING AND WANT TO SAVE SOME MONEY

Denso 234-4209 Universal Oxygen Sensor (Air and Fuel Ratio Sensor)
Approx. $32. This is the universal O2 sensor. It can be used as the upstream or downstream sensors. When cutting the connector off the old sensor, cut it close to the sensor so you have a long harness. You can always cut the harness shorter if you want, but you can't cut it longer.​

TOOLS AND STUFF
As always, there are tools and supplies you need to do the job that you might not have. You for sure need an O2 sensor socket and thread paste. EDIT: Some are reporting they receive a small tube of thread paste with the Denso sensors. If you do not order thread paste, and it does not come packaged with your sensor, a quick run down to your friendly neighborhood auto parts store will get you on the straight and narrow again. If you're splicing wires, you need a butt splice crimper. If the threads are dicey, you'll appreciate a thread chaser.
None of these are expensive, but if you don't have them you're going to pull your hair out.

PB Blaster Penetrating Oil, 12 oz
Approx. $5. PB Blaster will soak thru rusted fasteners making them easier to take apart. Typically you spray it on hours or even days before you want to work. It takes a while to do it's thing, and several applications are often needed. Tedious, but it beats rounding off hex heads trying to break loose frozen fasteners. Use this on the heat shield fasteners as well as the O2 sensors. It will make your job easier.

Lisle 12100 Oxygen Sensor Socket
Approx. $14. This is a suitable O2 socket, but it could be deeper. I was nervous that I had to kink the wires so close to the body of the sensor in order to get the socket on, but it worked. If I had to do it over, I'd go with...

Powerbuilt 648691 Oxygen Sensor Offset Puller
Approx. $8. This way the wires are not folded over.

Permatex 81343 Anti-Seize Lubricant 133
Approx. $3. Smear some of this on the threads. You don't need a lot - a little goes a long way. I have a bigger jar of it that comes with a brush, I'll probably have it forever, and it only cost me about $5. Oh yeah, use it on your sparkplug threads too. Keep a rag handy, this will get all over you worse than the maple syrup from your pancakes.

Lisle 20200 Thread Chaser
Approx. $7. You can chase out cruddy threaded holes for your O2 sensor and your sparkplugs.

Irwin Industrial Tools 2078309 8-Inch Multi Tool Stripper, Cutter and Crimper with ProTouch Grips
Approx. $17. If you don't have a decent stripper, cutter, and crimper, these are great.
​

 

[T-bone]

v000000000

 

[Audi_kraut]

Very well written. Thanks for the info and links. I know I'll be in need of this thread come install time

 

[karthwyne]

I recently replaced my sensors and can confirm this information. I went with the Denso sensors (which another member had coordinated with a Denso rep in Japan about and confirmed that they are the exact product that is sold to Toyota for OEM), and purchased that exact thread chaser.
The Denso sensor did come with copper anti-seize, so that product may not be needed.
As I was chasing down a code, I also purchased a multimeter and was able to use it to verify that the heater circuit was dead by testing resistance across the black wires on the sensor. This is the one that I bought, Equus 3320 Auto-Ranging Digital Multimeter. Should be less than $20

http://www.amazon.com/gp/product/B000EVYGZA/ref=as_li_ss_tl?ie=UTF8&tag=karthwynecom-20&linkCode=as2&camp=1789&creative=390957&creativeASIN=B000EVYGZA

 

[dogbreath]

I used a universal on the DS sensor. The only problem that I ran into was that the wire color did not match the wiring in the car. Once I figured that out, all was good.

 

[driftingsw21]

FYI if you buy bolt on Denso O2 sensors they give you antiseize. Least the one I got had a nice small tube even Denso branded.

 

[Keelaboosa]

Thanks all for the comments. I've edited my post to tell people they might pass on the thread paste since many of you are saying you got some with the sensor. If worst comes to worst and they don't get any, they can always hoof it down to the autobarn and pick up a tube.

 

[Keelaboosa]

I used a universal on the DS sensor. The only problem that I ran into was that the wire color did not match the wiring in the car. Once I figured that out, all was good.

Was it a Denso universal? What were the wire colors, if you remember? How did you figure it out?

 

[ThangCu35]

I use Bosch oxygen sensors and they are quality units as well. You can go to your local parts store and give them this part #: 15510. This costs $23.99 and is usually in stock.

It comes with a connector for another car, I just throw away that one and splice it with the oem connector. Use this chart diagram to splice together Toyota and Bosch.

 

[dogbreath]

Was it a Denso universal? What were the wire colors, if you remember? How did you figure it out?

No idea. It was well over a year ago. I figured it out by coming to this site and asking. Someone (it might have been Cap) answered up right away.

 

[Joe Schmoe]

 

[Keelaboosa]

Talking a guy thru this process the other day, I realized there's a step I forgot to mention when installing Universal sensors. When you crimp the wires together, don't cut all the wires at the same spot. If you do, you have a small wire bundle, then a big knot of crimps, then the continuing wire bundle.

Instead, stagger the cuts about 1" apart. This way you spread the crimps over a 4" length, but the bundle doesn't get real bulky.

Also, for peace of mind, you can cover these crimps with heat shrink. There's a lot available out there, but none of it is very expensive. I went with this.

Anytime Tools 48 pc HEAT SHRINK TUBING WRAP SLEEVES ASSORTED SIZES

Approx. $7. You get lots of different sizes, so this should also be a good addition to your electrical supply closet.

 

[luxuryrules]

Got a set of Denso 234-4209 on the way to (hopefully) correct a Bank 1 Rich issue.

Reading the chart with the wire colors, it appears that the sensors I have should be blue/white/black/black and the Denso should have the same scheme? But I also see some differentiation according to dogbreath's observations.

Could anybody shed some light on this?

Thanks!

 

[lexus005]

I have found http://www.stockwiseauto.com/ has been one the cheapest places to buy parts from. The carry oe replacement o2 sensors and were the cheapest on Timken wheel bearings.

 

[Keelaboosa]

Got a set of Denso 234-4209 on the way to (hopefully) correct a Bank 1 Rich issue.

Reading the chart with the wire colors, it appears that the sensors I have should be blue/white/black/black and the Denso should have the same scheme? But I also see some differentiation according to dogbreath's observations.

Could anybody shed some light on this?

Thanks!

The wire colors on the Denso matched the wire colors in my harness, so unless your harness isn't stock you shouldn't have any issues at all.

 

[jimlmathis]

After cat o2 sensor on a 2003 mr2 with smt

I have a question . Can you remove this sensor without removing the heat shield ? I have ordered this socket from Amazon , Powerbuilt 648691 Oxygen Sensor Offset Puller . Does anyone have any experience using this socket to remove this sensor ?


Thanks

 

[butch_mr2]

I have a question . Can you remove this sensor without removing the heat shield ? I have ordered this socket from Amazon , Powerbuilt 648691 Oxygen Sensor Offset Puller . Does anyone have any experience using this socket to remove this sensor ?


Thanks

You need to remove the sensor first before removing the heat shield. So there's really no need to remove the heat shield when replacing the sensor.
I just used that Oxygen Sensor Puller last week. I also soaked the oxygen sensor with PB blaster overnight, before I pulled the O2 sensor. Made it a lot easier to take out the O2 sensor.

Also, you can buy the Oxygen sensor tool at Autozone.

 

[jimlmathis]

Thanks ! I tackled the job today . I did just about what you described and had no problem ! BTW the densco sensors does come with a tube of anti seize compound .

 

[tmhuud]

Nice writeup. Thank you for this!

 

[luxuryrules]

Followup

I almost forgot to reply to this thread. Got the job done, went pretty smoothly. Good Guy Denso included tubes of antiseize in their box, fantastic! Quite a good move. Thanks all for this thread and the help.

Turns out it didn't resolve my P0172, but with the help of a few other threads I troubleshot my MAF, replaced, and all is working well now.

Thanks SpyderChat!