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Is the drivers side as difficult as some say? I have to do mine tomorrow. First check engine light this car has thrown in the time I've owned it
yes, to reach inside carpet is hard, if you have small hand is easier but is do-able, just take your time.
my suggestion is remove BOTH front wheels for two upper sensors, more room for you.
Maybe I just got lucky but I just finished up both front o2 sensors in about an hour. Prying the heat shield a bit away from the connector was all I needed to get a pick in there.
Bu comparison the front o2 sensors of my rusty ranger were a thousand times more difficult. If you have a clean LS and the sensors aren’t seized in the manifold, I’d put this at about a 4 out of 10 on the difficulty scale.
P.S. I cleared codes and ran for a bit, before all the incompletes cleared and I could go pass my MD emissions test, I picked up a P0430 code - Cat Efficiency Below Threshold Bank 2. I guess in the 6 months or so I've been driving around with the bad sensor before finally getting around to fixing it, the exhaust finally gave up. I'm at the muffler shop now and sure enough there a hole in the y-pipe under the heat shields. It all syncs up -- the new code, the increase in exhaust sound I noticed a few months back, the good info on that code I found in another thread here, the Kavanaugh hearings, etc.
I used this thread to replace bank2,sensor 1 on my 98 LS400.Reset codes.Cruised down mountain,cruised in town,slow light driving, and sure enough,up pops p0420.Hmmm,did i confuse the computer?
Reset codes and hopped on freeway doing 60-65 for about ten minutes,then drove hard up the mountain to get home.Figured after sensor was replaced I needed to heat things up? Got home....Cat monitor set itself as complete! YAY! Apparently per the internet a 10 minute drive at 60-65 is a generic way to set the cat monitor (wow,pegged that one!) after a p0420 reset if car is OK.Go figure!
So now i have 6 of 7 codes complete,and system evac inc.In Calif a 1996-1999 can have 1 incomplete readiness code,and 2000 and later can have system evac incomplete only and pass smog.Im heading in tomorrow to get that smog check.
BTW,for me this was a 2/10 scale of a job.Hardest part was getting floor jack and a safety stand out of garage.My sensor unclipping was a breeze with a tiny screwdriver and my 7/8 closed end wrench fit over the connector and slid down wires right to sensor.Came out with just normal wrench force.I have a clean no rust car so damn did I get lucky all around.
Great detailed thread,after reading it all I was ready and it went smooth as silk!
Very satisfying once completed, but it can be a rough journey...
I had to recently replace my Bank1 Sensor1, or, as I now call it, the Anti-Christ.
Thanks to all those that contributed to this thread. Here are my additional comments on the job, now that it’s done.
I had trouble throwing enough light on the subject. There’s not enough room for a conventional drop light, and I didn’t have a third hand to hold a flashlight.
One of those small flexible-neck LED lights would have come in handy.
Here are the tools I used/fabricated:
I used the crowbar to bend the heat shield.
Coat hanger wire is too thin for this job, but thicker wire rods work fine (I used thick wire salvaged from an old tomato cage).
The straight rod was used to pull out the plug, rather than use pliers to pull it out – I didn’t think there was enough room for pliers.
Using the extra-long drill bit, I drilled a hole in the old plug, then inserted the rod into the hole.
That allowed me to pull out the plug once the tab releases.
I never heard a “click”, as others have reported, so you might not want to wait for that click to pull on the plug as you try to push down on the tab.
As for removing the old sensor, I lucked out and didn’t need much torque to remove it (14 year-old car, but only 61K California miles).
But the conventional slotted socket didn’t do it for me- it extended out so far, that once I attached a ratchet I couldn’t find any clearance to rotate it.
Fortunately, it's easy to remove that small black plastic shield/splash panel between the sensor and the wheel/tire.
That allowed me to use the crow’s foot-style socket for both removing and installing.
I can see how removing the whole wheel might help, especially if the sensor is frozen, but I didn’t have that option since my car was on ramps.
Now for something some of you might not agree with – I didn’t push the new plug all the way into the socket.
If the replacement O2 sensor happens to be DOA (which you won’t know initially), the plug will be easier to remove later on if you don’t click it in.
In fact, the VSC and check engine lights went off after about 10 miles of driving, so I know it’s connected and working.
I might just leave it that way and see what happens.
It felt pretty snug going almost all the way in, so it might stay like that indefinitely, which would make the next replacement, if ever needed, much easier.
But if it somehow works its way loose, I’ll know that because the warning lights will come back on.
If it does, I’ll just click it back in, so, nothing really lost by trying this.
Sounds like 430 is a lot tougher than 400,i didnt have any clearance issues.But the general instructions here transferred very well to tackle the 400.I thank you all.
I went a step further and replaced the rear passenger sensor in my 2001 LS430. I couldn't find any pictures of the installation, so I figured I'd take some and post them here since this thread was so helpful in replacing the front passenger for me. The only thing I had to add to the instructions on removing the front passenger oxygen sensor was that removing the giant front plastic pan that covers the entire engine area from the bottom allowed for the right angle to unplug the sensor. After spending an hour (or two) trying to get it undone AFTER already figuring out the clip part, I just couldn't get it to slide out. Once I removed that panel, it slid right out for me!
The rear passenger sensor is attached right to the exhaust pipe and doesn't require the oxygen sensor socket to remove so you can use just an open wrench. I did have to apply penetrating oil as it was quite stuck and I didn't want to pry too hard on the exhaust system for fear of creating leaks. I gave it a good hour (or two) while I worked on the front passenger sensor which is detailed above.
So now that the penetrating oil has done its work, I removed the sensor from the exhaust with the open ended wrench. The photo below shows where the sensor came out along with the new sensor as I took this photo closer to the end.
Now we move inside the car into the passenger foot well. To find where the wire came through the floor I poked my finger up in the hole while under the car. My wife, who was in the passenger seat area watched for where the floor was coming up. It basically comes through in the left front corner of the foot well.
We determined that based on the drawings in the original post from the Lexus manual, the intention was to remove the air vent to gain access to where the connection is. To remove this vent, pull out from the side that is towards the rear of the car, this will release the build-in clip, and then slide the cover towards the rear of the car to pull the tab out of the slot.
Now you can pull the carpet out to the left and the right of the vent as you can see in the photo below. The wire travels from the front left corner of the passenger foot well until it reaches the vent height, and then takes a 90 degree turn towards the back of the car. When you first reach your finger in you’ll find it just below the vent. Towards the rear of the car, to the left of the vent is where it clips into the wire harness.
Towards the front of the car, to the right of the vent, there is a clip that holds the wire to the plastic frame which you will need to remove. Squeeze the tabs on the back and then pull it through the hole, should be easy to remove. I’ve included a photo below which shows the oval hole after the clip was removed.
Now that I had the whole thing disconnected, I decided that I would put the new wire in before removing the old. I figured that if I couldn't get the new one in for some reason, it would be bad to take the old one out. So I took the new wire and used the wire tie that came with it to tie the rubber outer layer of the wires to the clip on the end of the wire. This prevented the outer rubber casing from getting bunched up while I slid it through hole and under the floor. From under the car I fed it through the hole while my wife put her hand down behind the carpet around the air vent from top side. She managed to grab the end of the wire and pull it through and plug it in.
Now secure that we had everything through set as far as wire fishing, we wrapped the clip on the end of the old wire with electrical tape to prevent it from getting snagged and I pulled it through the hole under the car while my wife guided it through the carpet. At the end it got stuck, but I gave it a good tug and it came through. With the old oxygen sensor now entirely out, we applied the anti-seize compound to the threads and screwed it in. I then pulled the rubber casing down the wires to cover the wires that were exposed under the car.
I haven't reset the codes yet because the last time I did I had to reset the vehicle stability control entirely.
There are a bunch of clowns who are cutting up carpets on youtube. Thanks to this post I didn't have to
- You don't need any of these fancy sockets.
- Get a 22mm wrench with an offset closed end.
- Penetrating oil helps a ton.
- Take the front two wheels off and it'll give you a lot more space to work around, making your life a lot easier.
- Get the correct part number for the upstream sensors as they are car specific wideband.
- The pry bar is useful to disconnect the upstream sensor on the driver's side as the heatshield is in the way.
- Down stream sensors don't even waste your time getting the correct part number, just get the universal one snip it under the car and solder the new ones on.
Directly after I replaced Bank1 sensor2 O2 sensor my Nav system has an error that it cant read the data and to check DVD version. Is it possible that I pulled some cable or connection while getting the O2 sensor installed ? It seems to be too much of a coincidence that the Nav error hit just as I worked in the driver side area close to the stereo wire harness. Thoughts?
I have a problem no one has shown yet I thought I had the clip released and I pulled the plug off the wires.
I pulled the wires through to the engine compartment and then put extenders on the wires. I then pulled it through and wired the o2 sensor up and works great.
Ian
Hi ian,
I have exactly same problem with my B1S1 (in the engine compartment) . Judging by what you described, yours seems like same sensor.
I didnt have any success from the bottom of the vehicle for there is absolutely no space and it is impossible to see the harness from above. Could you provide some detail description as to how you resolve the issue??
Thanks!!
Replaced both sensors 1 (bank 1/bank 2) in response to CEL. I've done a lot to cars with help from forums such as this but this one was a bit more challenging. I was successfully able to replace them but what an absolute b***h those clips were!!! After reviewing everybody's suggestions several times over, what seemed to finally work for me was bending that heat shield a bit on drivers side (Bank 1). Did a dance when I finally got that mohfho loose. The sensors screwed in and out smoothly, thank goodness.
Thanks to all of the tips and tricks provided here!
Just replaced all 4 O2 sensors with Denso parts. This thread helped me a lot. But what a pain in the butt, the front sensors and connectors are really difficult to get to. However, it helps to remove the small engine bay cover in each wheel well. Was able to fit a torque wrench through there.
The rear O2 sensors are even worse, because of the stiff anchored carpet hiding the wires. Spent almost 2 hours each on the rear O2’s. Can probably do it in half the time now. I recommend cutting and soldering the old wires for those who want to save some time and a headache.
12-07-18, 07:48 AM
