Originally Posted by DanozLS430

I completed this task and added this info into the GS forum and thought it belonged here.

I had a problem looking for someone on this website to show me how to install and located Bank 1 Sensor 2 02 sensor for my 2000 Lexus GS300. After doing research and finding a great 02 sensor part guy on ebay I took on the challenge and found it very easy to do once you get the right part and tool to do the job.

Tools needed or what I used:
* Stanley 3/4 drive expandable ratchet
* 02 Sensor removal socket wrench (to remove the 02 sensor)
* 10mm socket 3/4 drive (to disconnect battery cables)
* Small flat head screwdriver (to detach sensor male and female part)
* Liquid Wrench by GUNK or other lubricating spray to loosen sensor
WD40 would probably work also
* Small flashlight to locate sensor from top of engine
* 02 Sensor Part #14260 from PartREX - ebay name te_x_as
Great communication and excellent support from these guys. The cord length was a little shorter than the original but had enough slack and more to finish the job. I think you can also use the same sensor part for the front one which is bank 1 Sensor 1.

** Photo taken with hood up and looking down into the engine on the passenger side. Bank 1 Sensor 2 is the bottom one circled in yellow. Easy to remove with the Stanley 3/8 drive expandable ratchet.

I listed the tools used and also the correct sensor to change for Bank 1 Sensor 2. The expandable Stanley ratchet was bought from Wal-Mart and came with standard socket set, not metric which I wanted. Paid about $28 for it. The 02 Sensor removal 3/8 drive socket wrench was bought also from ebay for $7 + $5 shipping = $12 from ebay name up4salebytaw. I seen it at Checkers Auto later but don't remember the cost. Liquid Wrench by GUNK was about $2.29 at Wal-Mart also. I know the LEXUS dealer would charge over $250++ to change it, so I tried and found it very easy to do.

1. Park your car in the shade, lift engine hood, wait 1/2 hour until engine is cooler so you can spray the Liquid Wrench around the base of the sensor. FIRST DISCONNECT THE CAR BATTERY (negative side first, positive side second ) once you know the error code (P0141) and before you start spraying or removing anything.
2. After 1/2 hour respray another small dose of Liquid Wrench around sensor and unhook 2 plastic black clips that hold the sensor wires together.
3. Remove the sensor socket area (which is attached to the car) by sliding it in a forward motion. This will make it easier to attach and see how the sensor fitting fits.
4. With a small flat head screwdriver look at the gray female sensor area where you can put a flat head screwdriver to push down a release clip. Keep the clip pressed down and pull apart. The male and female part will easily come apart when pulled.
5. Next attach the 02 Sensor wrench socket to the bottom Bank 1 Sensor 2 Sensor and once fitted on, attach your expandable ratchet and set it for left to loosen.
6. Loosen sensor by pulling up on the ratchet handle loose.
7. Remove 02 sensor wrench and unscrew the rest by hand until 02 sensor is out.
8. Wipe down with paper towel the sensor area where you sprayed the Liquid Wrench.
9. Hand tighten the new 02 Sensor (te_x_as part #14260) and finish tightening with 02 sensor wrench and ratchet until tight as an oil drain plug. DO NOT OVER TIGHTEN or you may strip the treads.
10. Attach gray plastic male end to female end.
11. Slide back and attach gray plastic male and female part to clip on body.
12. Put back black plastic wire holders.
13. Re-connect the battery terminals with 10mm socket. (positive side first, negative side second)
14. All Done. You will have to reset your radio stations and A/C settings again.
15. Done fast and easy without even jacking up your car!

I hope this helps all who wants to try it themselves. Very easy to do once you find the trouble code using the OBDII scanner (bought from eaby also) and having the right parts in hand. My car CEL (cehck engine light) never came on since and gas mileage improved. Now gettng 22 MPG city /hwy combined. For Hawaii driving that's great! GOOD LUCK!!! DanozLS430

Originally Posted by natedahms

The part numbers for the oxygen sensors for 99-00 GS300 on oxygensensors.com are incorrect. I ordered oxygen sensors for bank 1 sensors 1 and 2. Each costing 100+ dollars. I installed bank 1 sensor 1 and took my GS to Lexus to have the EUC reset and to make sure that was the only problem making my check engine light come on. I was told that the sensor I installed was not working correctly. I wasnt sure if they were telling me the truth since I didnt buy the sensor from Lexus. You know how that goes. I was also told that I needed to replace bank 1 sensor 2. I ordered that sensor from oxygensensors.com as well. I recived it today and went to install it and noticed that the numbers on the sensor didnt match the one I had just taken off my car. I did a search on google to see if these numbers checked out or cross refernced but instead I found a thread on CL where other people were having the same problem I'm having getting the wrong sensors from oxygensensors.com. I called up oxygensensors.com and was questioned as to weather or not I knew what I was doing. I worked on cars for a living longer than oxygensensos.com has been around. I told him that the numbers on the sensor its self did not match up. He told me that the numbers on the sensor had nothing to do with a part number, that they were just a referance as to where they were made. I know better than that so I looked up the numbers on Denso's website and found the correct part numbers. I hope I get this all straightened out. I already put one of the sensors on the car so so much for getting that money back or exchanging the part. Now I see why there sensors are so cheap. You end up paying 200+ anyway....

the correct Denso part numbers are:

(1,2,3 precat) Bank 1 Sensor 1: 234-4048

(1,2,3 postcat) Bank 1 Sensor 2: 234-4626

(4,5,6 precat) Bank 2 Sensor 1: 234-4630

(4,5,6 postcat) Bank 2 Sensor 2: 234-4603


oxygensensors.com has part numbers

(1,2,3 precat) Bank 1 Sensor 1: 234-4048

(1,2,3 postcat) Bank 1 Sensor 2: 234-4622

(4,5,6 precat) Bank 2 Sensor 1: 234-4626(4,5,6 postcat) Bank 2 Sensor 2: 234-4603