RoX300

OK. I think I found replacement tap-end studs not intended for this purpose but I think they'll work.

They're Dorman Threaded Metric Fasteners, Double-Ended Studs Class 10.9 Part Number 675-330.1

"A" Thread Size : M8-1.25
"A" Thread Length : 20mm
"B" Thread Size : M8-1.25
"B" Thread Length : 10mm
Shoulder Length : 0mm
Overall Length : 30mm

I special ordered them at AutoZone and should be able to pick them up tomorrow. I'll let you know if they work. I've attached a picture.

RoX300

Here's what I have:

1. Denso Oxygen Sensor
2. Two (2) tap-end studs to replace rusted originals. These aren't designed as replacements but they appear to be an exact match. They're Dorman double-ended studs part number 675-330.1. I got them for about $ 1.50 each from AutoZone.
3. Two Lexus replacement nuts part number 90179-08059. These cost about $ 5 each. I think Lexus has a 500% margin on all parts.
4. I also have two M8 nuts that fit that I got for about .18 each from Home Depot that I considered using but I think I'll stick with the specialized Lexus nuts.

Now I am debating whether or not to try to track down the Heated Oxygen Sensor Protector (Heat Shield) that fell off of mine (Lexus part number 89437). I see in some of the repair pictures that others like LexMex are not bothering to include these when they complete their downstream O2 replacements. If I can't find these for a reasonable price at Toyota or Lexus tomorrow I'll proceed forward with the project. I've also included pictures of a couple of others that did include the protectors to show what they look like.

I've also included a diagram for the assembly of all of the components.

RoX300

I called around this morning to five local Toyota and Lexus dealers to get a price on the Heated Oxygen Sensor Protector (part number 8943748010 - Cover, Sensor). The quotes ranged from $ 32 to $ 18 with the lowest surprisingly being one of the Lexus dealers. None of them had it in stock. It has to be special ordered. I'm growing impatient and will proceed with the installation without the heat shield as I've seen many others here have done.

I'm also considering using Loctite Threadlocker Blue 242 since these are components that will experience a lot of vibration. It also protects threads from rust and corrosion which we have all seen as a problem here.

Any comments on not including the head shield part and using the blue 242?

salimshah

Check for temp rating. My first thought is that loctite will become carbon. If you do find the right product, make sure the thing can be broken when a replacement is needed. [Lots of thread lock burn off when you heat them ... that is why heat is used to break the bind on thread-locked bolts]

Split washer with large face bolt (which typically Lexus uses) are the best things use. Large face nuts/bolts eliminate the use of a flat washer.

Did I mention stainless steel product for any after market solution.

Salim

RoX300

Thanks Salim!

RoX300

Finished the job. The two (2) Dorman tap-end studs I used to replace the rusted thread stripped originals worked perfectly. I recommend replacing the original studs rather than attempting to clean and re-thread them.

carguy07

So do the original ones thread into the exhaust? You just grab them with a vice grip and thread them out or did you have to drill them out? Thanks.

RoX300

What happened with me is that the nuts had rusted off and the O2 sensor fell out and was banging under the car. I found a couple of nuts and tightened them back onto the rusted studs on the rusted threads. When I took the nuts back off they had pretty much fused together on the bad threads and the studs unscrewed with the nuts when I took them off. Not sure if you could recreate that process but once I had them off I was able to track down the dorman tap-end studs as replacements and they were a perfect fit. I then had a choice of using inexpensive nuts I bought at Home Depot or expensive ones I got at the Lexus dealership that are designed for that purpose. I ended up using the Lexus ones. I see that others have also removed the studs and then rethreaded them. You might ask them how they were able to remove their studs. Good luck!

salimshah

There are tools to remove studs and if the exposed threads are good, one can use two nuts to lock and then undo the stud. Some times the studs are frozen and too much force can shear them. Then you have to drill them out and re-tap the threads in the bore.

Salim

SC400DAVE

Great write up guys! My check engine light came on the other day and its this sensor!

Thanks a lot!..........

sylvia

hi guys , I am not a mechanic but I was told the OS needs to be changed on my RX300, 2001, 124K, the check engine light came on but I have no idea what the code is. I have two questions and I am not sure you can help but there I go:
1. what should be the code?
2. can I check if I can buy the censor on line from US as I am in Canada now, what is the part number and where do u suggest i search for it, amazon.com?

SC400DAVE

If you can afford it, change all three if they have never been replaced.

https://www.oxygensensors.com/

sylvia

Hi guys, my car gave reading P1130 bank 1 censor 1. Could you help me with the part number
is it Denso 234--4215 or 234-9009 or a totally different ?
Thank you again,
Sylvia

Baetke

Air Fuel Sensor(Toyota) 89467-48011
Air Fuel Sensor (Denso) 234-9009

Baetke

Your diagram has erroneously labeled the sensor as Bank 1 Sensor 1. The correct designation is Bank 1 Sensor 2 for the O2 sensor.