RX300CE

I did it by myself, I drove a car on Blitz Rhino Ramps, go under of RX one right hand press tab down, one left hand pull plug out, it took me 30 minutes done a job, couple days before that I sprayed alot BP blaster penetrating around threads .

salimshah

Working from below is totally different when you think of 'at home' vs 'at shop'. At home you are essentially on your back. If you roll on a side to increase your reach, the other hand gets pined down. At shop you can bend your knees or raise/lower the vehicle and both arms are available.

Mechanic has experience and his learned techniques. And they do have help ... it is a team environment. Dont expect two master mechanics working on your RX to change the sensor .

Salim

BlueCrabby

Does the the sensor unscrew clockwise or counter-clockwise? I'm about to start doing it...
I figure it's best to have all the right info. Don't want to start by tightening the sensor.

carguy07

righty tighty lefty loosey

salimshah

But dont go un-threading it all the way. Loosen 1/4 turn and tighten 1/8, better still pick a smaller number. Shoot some penetrant in between to help preserve the threads.

You should have a replacement sensor before you try to remove the old one. You can always use your finger nails to figure out which direction of twist will take it out.

All threads that I know of are Clock-wise to tighten and Counter Clock wise to remove.
Exceptions are:
The secured object rotates and can cause unthreading.
Tamper prevention.

The sensor does not qualify for either.




Salim

BlueCrabby

Last question, I promise. After I'm done with the job, which battery terminal do I unplug to reset the CEL light? The positive or negative? I have always pulled the negative terminal when doing
other car electrical jobs(for example, installing fog lights). However, it just occurred to me that
most people say to pull the positive terminal. Is there a difference?

Thanks!

salimshah

First a correction .... Before you do the job disconnect the battery. Remember to allow about five minutes (being safe) from the time you pull the key out of ignition to disconnect the battery. When you are done, reconnect.

Which terminal ,,,, the one that connects to the body (chassis)... that is the bare wire. That should be the negative for RX.

Salim

BlueCrabby

I drove my RX300 up the Rhino Max ramps. Used two heavy-duty chocks to block off the rear wheels securely. There was just enough space for me to reach the connector and the sensor. When I'm down under the RX300, there's about 4 inches of space between my chest and the RX300 stablizer bar.(the black metal bar) After all these years, this is the very first time that I looked at the bottom of RX300.

I reached my right arm up and attempted to disconnect the connector. After several tries and a very sore index finger, I managed to press the tab down enough for my ring finger and pinky to pull the wire. The connector came off quite easily. I though it was going to be hard to do this without help, so I'm glad I got it off.

I went back inside the house and waited for UPS to deliver the sensor, offset socket, sensor socket and a box wrench. I ordered all since I had no idea which one would work best given my large hands. The UPS guy always shows up before 3pm, so I was a bit concerned when he didn't show by 4pm. I checked the tracking page and apparently the package was mis-routed. It will no be delivered tomorrow. They have my correct address, but somehow it is now two states away.

Now I have my RX300 with the sensor connector dangling down there. I guess I'll just leave it like that. If I plug it back in, who knows if I'll be able to take it off as easily as today?

Without thinking, I started the engine and back it down from the ramps. As soon as I shut off the engine, I realized that the engine ran for 20 seconds with the B1S1` sensor disconnected. Hope I didn't do any damage. I just assumed that the engine will still think it's a bad sensor.

Well...to be continued tomorrow.

fastnoypi

You're lucky with that connector, it took me longer to pull the connector off than actually replace the sensor. No need to worry about starting your car, these modern ecu's have a way to put itself in a "safety map" in the event of a bad front o2 sensor. If anything it probably ran rich for those few seconds you drove off the ramps.

salimshah

So you did not follow my advice ,,, disconnect the battery.

Most likely nothing bad will happen, but the safety is an interlocking mechanism. Had you disconnected, and tried to start ,,, that would have been a reminder that "no can do" ,,,, engage brain .. do I need to start .. etc.

Salim

BlueCrabby

yes, I did disconnect the battery once I drove the RX300 up the ramp. My mistake was
that I was counting on UPS to be on-time. I unplugged the sensor connector then waited.

Since the package got delayed, I had nothing to unscrew the sensor with. More importantly,
the new sensor was also in that package. When I found out that the package was mis-
routed and wouldn't be delivered, I went outside and connected the battery. Started the
RX300 and backed it down from the ramps. (forgetting that the sensor connector was still
unplugged) My bad.

When the RX300 detected nothing because of the unplugged connector, wouldn't it just
assume that the sensor was completely dead?

salimshah

Some sensors control the current and some send a voltage out. By the testing procedure it seems this sensor is current based. These sensors you do not connect/disconnect with ignition on [well you can, but you may cause damage]. With ignition off (even better with battery disconnected) you should be fine.

There are few sensors which monitor ignition key on and loss of power ... potential accident condition and they light up air-bag idiot light.

Lets try to keep other discussion out of DIY thread.

Salim

BlueCrabby

Applying the anti-seize compound that came with the new Denso sensor.

Does the Toyota factory put anti-seize compound on the sensor's thread
during the production of the RX300?(or any other Toyota/Lexus vehicles)

Briand_OH

Yes, factory and most mfrs apply anti-seize. IMO is best to heat up the sensor prior to wrenching. I've had success with a 6-pt 7/8" (22 mm for all practical purposes) Craftsmen combination wrench in removing 'cause you can hammer on it. YMMV.

BlueCrabby

I left my RX300 sitting for 3 days without starting it. (except for a 20-second period to
back it down from Rhino Ramps)

This morning, I finally received the Denso sensor and oxygen sensor socket from Amazon.
I immediately drove the RX300 up the Rhino Ramps.(again, only 15 or 20 seconds of engine
run time, so everything under the hood was very cold... or as cold as the outside temperature
which was 65 degrees) This is bank 1 sensor 1.

Since my connector was already disconnected days ago, I fitted the oxygen sensor socket
on the sensor and used my small 8-inch wrench. No go. The sensor wouldn't budge. Next,
I sprayed PB Blaster liberally and waited a couple of hours. Still no go. Since the 8-inch
wrench is my only one, I drove my other car to the local Walmart. Found an adjustable
3/8" wrench made by Stanley. It can go up to 14 or 15 inches. Drove home and tried it.
The sensor made a pop and immediately loosened up! The wrench probably only moved
1 inch. I was able to unscrew the sensor very easily with my hand. Thr thread felt fine as
I backed the old sensor in and out a couple of times to check.

I applied the anti-seize compound on the new Denso sensor's thread and made sure I didn't
get any on the sensor itself. Carefully screwed the sensor in and tightened it by the wrench
by about 1/8" to 1/4"? Plugged the connector back in. Reconnected the battery, started
the engine, backed down the Rhino Ramps. No more CEL and VSC light or P1135 code!
Yay!

I want to give big thanks 81corolla and salimshah! p: I couldn't have done it
without the advice you guys provided. You save me at least $200. Both of my local Lexus
dealers wanted $450 for the job... the Toyota dealer wanted $370.... independent
Lexus mechanic wanted $$290. My cost was just the sensor from Amazon($115 when
I ordered it), oxygen sensor socket($8), and a set of Rhino Max ramps($54 at Amazon,
but I used a couple and bought them for $43 at the local Advanced Auto Parts)

Also.... now that I have a spanking-new sensor down there, should I go ahead and
order another and swap out the bank 2 sensor?(the one behind the radiator) That one
is also the same age(100k+ miles, original). Will that produce any noticeable result
as far as daily drivng goes? Thanks again!