Magda

that's very useful info. Thanks
That's why it reads somewhere that a trained technician should service them because there are those hidden screws? It may be why they don't pull out when being pulled ( i did not pull strongly or used force as I suspected that the procedure for those big fuses may be different)

dicer

The goofy drawing in the manual made it look like a normal fuse. I will have to take one apart some time to see for sure. The relays do pull out.

Magda

I just wonder how you did remove your fuse Maybe I will keep mine for now.

dicer

The small ones I just use needle nose pliers. The big ones I have not removed yet. Maybe someone else here has??? So did you check that O2 voltage yet?

aptoslexus

From post #8 here: http://us.lexusownersclub.com/forums...e-replacement/

1. Remove the battery. You'll need the room.

2. Remove the single nut attaching the right side of the cartridge container.

3. Lift the container up off the plastic post holding the left side to the main fuse container. This post snaps into place, so use a tiny screwdriver to bend the plastic loop of the cartridge case, releasing the snap. (If that's not clear, just shove a screwdriver in there and wiggle it around until the case comes loose.)

4. The cartridge case is now free, attached only by the dozen or so wires coming out the bottom. These wires are all bolted to the sides of the fuses. The reason you cannot see this is that the sides of the cartridge case are actually tiny flip-up doors -- which (of course) are snapped shut. Stick above-mentioned tiny screwdriver under plastic snaps and open the flap on each side of the case.

5. There they are! Remove one bolt from each side the the 120A fuse (or whichever fuse you need to replace).

6. Grasp the top of the fuse with needlenose pliers and pull it up & out.

Magda

I did not check O2 voltage. I will before changing ECT sensor - I need to order that one. Thus I will get to it probably within a week. At this time I don't have a time pressure to fix the car... But I will keep you posted on my progress. Thanks for your help.

Magda

Thank you for that - I may use those steps at some point

Magda

Dear Dicer,
I did test voltage Vdc between OX1 and negative battery post.
Below is the YouTube movie and excel sheet graph I made based on the movie. I wrote down the multimeter readings and correlated then with RPMs at subsequent time points. The engine was not very warm as you can see from the temperature dial of the dash. However my problem occurs at those conditions.

Observations presented here were made BEFORE changing ECT engine coolant temperature sensor.

Vdc OX1-negative terminal and RPMs (in this video I turned the car with cold engine after a few days in the garage so you can see how RPMs are gradually going up until the fluctuating idle begins):

20151222_OxygenSensor1_voltageTestWhileFluctuatingIdle_readings.pdf

The same was done for OX2:

20151222_OxygenSensor2_voltageTestWhileFluctuatingIdle_readings.pdf


The values are approximate and sometimes it was difficult to catch all changes so keep it in mind
Also I assumed that .0L means 0mV !!!
I wonder what's going to happen once I install new sensor.

Happy Holidays to all of Lexus Fanatics

Magda

I'm in the process of replacing the ECT sensor. But the deep sockets I have are not deep enough with hexagonal crosssection so that sensor is too long for them and socket does not reach the hexagonal bit of a sensor... This plastic connector prevents the socket from getting ahold of sensor. What to do?
I will probably figure it out eventually...

dicer

Okay so how warm was it? If the highest it went is .18 volts, either you have a bad o2 sensor or something is causing a very lean condition, like fuel pressure regulator, vacuum leak too much idle air. So how did the other o2 test? Do the ect change and then recheck it. When at operating temperature.

Find a better socket. I think I used a craftsman.
Okay ran down and checked a spare I have a 19 mm 6 point craftsman fits good.

Low o2 is lean and high is rich. I got it messed up. Low o2 adds fuel and high removes fuel.

Really need to check both the O2's for voltage. If the other one fluctuates good then you have one bad one if both are low. Your looking for either a vacuum leak, or something like a low fuel pressure. Maybe the egr leaks or some gasket or hose. We don't know till the ect and you check both o2's.
Other things that can cause o2 sensor not to show right could be electrical connection and the heater circuit etc. Have the O2 sensors ever been changed?

Magda

Thanks for your response.
First video and PDF graph is for ox1 .


Second video and pdf is for ox2.


Also I forgot to add that I had multimeter set on auto ranging thus it shows readings in Volts and in millivolts in the video.
Once you look at graphs you will see all in millivolts. It goes up to 1800mv which is 1.8volts... I tried to make it clear but sometimes it's a bit tough to do that.

Thanks for your help

Magda

By the way, the engine was not really that warm. I just turned it on and measured in first video. Then I measured for second video. You can see the temperature gauge on dashboard in the video.
I may have to run it more... But the matter of fact is that I observed my symptoms at this point and I do not want to run my car too much like this...

Also in most cycles of 800 to 1200 rpms there was a moment of .0L which I assume means 0v. See graph.

I will try to find craftsman deep sockets.
Thanks
Magda

Magda

At least one of those O2 sensors was replaced 1 or 2 years ago. Need to check records.

dicer

Its bad to just replace one when there are two. Craftsman are at sears stores. Oops I didn't see the pdf for the other.

Okay since they are similar likely O2's are okay, so after you change the ect check the volts again. And what you can do is pump the accelerator a bunch of times while watching the volts, don't rev it high just kinda pump it like your trying to add lots of gas, the volts should go up.
The egr is a guess for the vacuum leak if the volts stay low normally when not pumping it. There is a test for the rich o2 response other than trying to pump the gas pedal which you can do at the throttle body(where the throttle cable is) so you can watch the volts. The other test is to use a propane torch and with no flame just add some gas in the intake, but I don't think its a good idea for the airmeter to add it there. I'd have to find more info on that. I think the pumping it should show enough.


I sort of reread some of this, and you said it all started after the work you originally did. You really need to verify all the gasketed joints that you worked on are sealed and not the source of the leak, and all hoses are okay and connected correctly. Pull the pcv valve and hold your finger over it when running. (And where did you get the new grommet for the pcv?) Does it change the o2 numbers at all? You can also use your hand held vacuum pump to operate that egr and see how that affects the O2 volts too.

dicer

Did you ever try checking for codes? Please do.