i just wanted to the thank OP for the detailed pictorial. i replaced my b1 s1 today. first time it was hopeless, i didn't know about the tab i had to press and i didn't have the sensor socket. i tried to actually unscrew the sensor with an ordinary adjustable wrench!

thankfully once i had the proper knowledge and the socket, it was a quick job. i had sprayed wd-40 several hours ago and i had the breaker bar as well. it came off quick and didn't have to resort to blow torch or anything serious.

thanks again!

 

Did the front one today. Took all of 10 minutes. Kinda miss the trio of warning lights... NOT!

 

Great thread, thanks everyone.

And would like to clarify for people, there is no b2s2 (bank 2 sensor 2)

And the b2s1 and b1s1 are "upstream" and the b1s2 is "downstream" (this one is always the cheapest, so don't be fooled into buying it thinking it will work on the upstream side of things)

 

So, I went to soak down the nuts on the downstream b1s2, and low and behold, one bolt is broken and the other one's nut is missing. Anybody care to guess the nut size? I assume metric. And since the gasket has deteriorated, would exhaust sealer/cement suffice? Might use one nut and a large hose clamp to hold the thing on tightly. Any thoughts?

 

I have yet to discover an exhaust cement/sealer. The temperature gets very hot and even jb-weld gives up.

You need a a leak free setup. I would suggest going to an exhaust shop.

Salim

 

Just joined the forum today too and getting ready to replace the two AF sensors. I originally thought I need to just replace the 02 until I read these posts and then running the codes, 1150 and 1155. Looking forward to an easy install including the connectors...I hope. I believe the alternator is next, making a lot of noise around the bearings.

Bob

 

Finally received my parts today and completed both AF sensors replacement. I had a devil of a time with the connectors but found that if I used a metal socket on my finger I was able to put more force on the tab. Also, I did not have a cheater bar so I picked up a curved conduit pipe from HD which worked perfectly. See pic below. I want to thank everyone on this thread and the others I read for the excellent information as I saved a good bit of money vrs taking to the shop. Now to see if the trouble light stays off.

Bob

 

Thanks to the OP on this thread, though it took more than a 1/2 hour to unplug the sensor, everything went smoothly.
As a tip to get more room to get at the O2 clip from the top, temporarily move the throttle cable and bracket out of the way. Use a 12 mm open end on the nut on the cable and 12 mm socket to remove the bracket. This might be usefull for those with big forearms to reach down and press down on the locking tab.

 

I have to second that - very helpful pictorial and step-by-step instructions for the two upstream sensors. Did both in less than an hour and the hardest part was un-clipping the wire harnesses! While I don't need to replace the downstream sensor yet I'm curious how that's done, because it looks quite different - I see here in the thread others are wondering the same. Does anyone have experience with this?

 

Are you talking about port1 sensor or downstream sensor? [edit my bad .. you do state upstream ]

Port 1 sensor is accessed from below. I prefer a box wrench with a deeper offset. Electrical clip is easier to reach from above ..[try from below too].

Port 2 sensor is above an right next to the radiator.

Downstream sensor is where you have to cut the carpet underneath the driver's seat.

For anything in the exhaust ... remember to work the sensor ... unthread and thread it back to preserve the threads.

Salim

 

New to this forum and was able to replace my bank 1 sensor 1 with very little trouble following the directions. less that 15 minutes. Thanks again

 

B1S1 died on me again (this time not under warranty). Ordered off Amazon and figured I would have it in few days. Well the car kept having full on convulsions and clearing the code was not buying me any time. I check Amazon and they are still sitting on the order and estimating a week + to get it in my hand. So I figured I would see how far out Advance Auto was on price so I could get it fixed this weekend since it's warm and the car is basically underivable. Even with a coupon code they were $30 higher, so I was on the fence whether I should wait or pay extra and be done with it. Just for grins I chatted with them on-line and asked them to match amazon. Took them a few minutes to see what they could do. To my amazement they matched the price (yes I still had to pay tax,). You need to have an account with them to do a price match, and they phone you for payment. Anyway, super happy with Advance Auto on this one. I was able to cancel the Amazon order too.

I used this socket



http://www.harborfreight.com/78-oxyg...ket-69022.html

and this awesome extendable 1/2' ratchet from Harbor Freight




\http://www.harborfreight.com/1-2-hal...het-98831.html



Got lucky and it came apart and went back together easy.

Thanks to the guys on this thread.

 

Edit:

I found the location of the plug, but unfortunately my freakishly big hand can't fit into that opening.(left or right hand)

Is there another way to easily disconnect this?

Thanks in advance for your help!

 

Get some help. One person from above to squeeze the release and one person below to pull the plug out.

Not easy but can be done.

Salim

 

Is the plug impossible to release from under the RX?

There's gotta be some way to do it with just one person. I can't imagine the mechanics at Lexus dealers asking for help to release a plug like that. Or perhaps they have some special tools/gadgets to do it?

Thanks!