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I was changing out my O2 sensors today. So I decided to take a bunch of pictures of how I was able to remove them. There are to 2 great links from the UK owners across the pond. See links below for reference that help understanding what has to be removed, or not. Keep in mind the UK spec are opposite of our USDM cars. That's why I wanted to upload the pics as more visiual references. In total like stated in the links. It's roughly about a 2 hr job for both banks. PB BLASTER does help use it. B2 S1 takes some effort to remove. I used a 12" pipe to slip over my 3/8 drive ratchet. Then removed the bracket that holds the ECU main harness. Along with the ground strap (mines not OEM), and fuse box out of the way. Finally I was able to torque them back to 32ft lbs. Not sure if it's correct as I just skimmed through a few diagrams. Which showed the spec through out the years from LEXUS platforms.
The DENSO first time fit are a little longer wiring harness than OEM.
DENSO B2 S1 234-9068
DENSO B1 S1 234-9048
My car is an AWD so according to Jeff Lange. These are the numbers:
89467-30040 Passenger Side (RH) Upstream (Bank 1 Sensor 1)
89467-30030 Driver Side (LH) Upstream (Bank 2 Sensor 1)
89465-30730 Passenger Side (RH) Downstream (Bank 1 Sensor 2)
89465-53230 Driver Side (LH) Downstream (Bank 2 Sensor 2)
Mike, just curious, I'm assuming you replaced them because they needed to be done, or are you replacing them just to replace them?
Yeah the wierd thing is at 70-80k my igntion coils started failing both banks. I replaced bank 1 first all of them. That solved my idle misfire. Then I was still left with bank 2 still had problems. I couldn't rev past 5K. I would get a back fire, and the car felt like it was dragging. So replaced those also with new ones.
It solved my issues there, but my mileage is still suffering big time. I graphed the the bank 2 sensor, and it was reading lazy. So I decided to just replace it along with bank 1.
This whole time I've had no codes at all. So I still have to replace my bank 1 sensor Saturday. As for now I just decided to break it loose so it will be a faster install, and take pictures LOL.
Bank 2 today after installing it's not lazy on the graph anymore. So hopefully replacing bank 1 solves my my fuel consumption. I'll still have to let the ECU learn again before I start looking at my fuel trims. If not I'm at a loss here as the car still pulls hard. Though I do smell raw fuel sometimes.
Checking my scan tool while cruising everything looks good.
It's just later on after a an ECU reset. My fuel trims at Bank 1 are -13 always at idle, and bank 2 will be like +4-7 at idle.
So hopefully changing bank 1 sensor it will do some good.
This still have all 4 cats? What was your MPG and what is it now?
And can you post your STFT & LTFT @ cruise?
What I have found is collecting data early on when all is well is a huge help when things go south.
Like having fuel trim data and O2 sensor data from early on to compare too that makes diagnosis easier when things do go wrong.
Just a suggestion, I'd think that if a cat were plugged it would limit high rpm/high load pulls but you state it pulls great. Have you looked at ignition advance? If it's crippled by say a bad knock sensor it will hose your MPGs and limit performance.
Yes the car still has all 4 cats. Milage is a little over 82k now. The car has been having issues since around 70k. All of a sudden my gas mileage is starting to decrease. I find myself having to fill up more often than before. Even my MPG display on the tach will jump around like crazy. While driving it will go from 18-24 mpg. It will cycle like that. Though since I've swapped all my ignition coils it has stabilized.
Before my issues arose it was a constant 24.1-2, but would never bounce up or down. My driving habits haven't changed. Calculating with trip meter to gallons on fill up. I was averaging 22.3-5. now I'm at around 19-20 at best.
Yes it would be good to have a bone stock data on how a healthy Engine should be running. For reference to pin point something out of place.
What I mean while out cruising. My fuel trims will be closer to zero STFTS will be around 0 vs LTFTS will be close also bank 1 -2.3, and bank 2 will be at .8.
What's weird is that before I replaced anything the fuel trims at idle would be at -13 bank 1, bank 2 -7. Though I could definitely feel the car not running right, and idle miss fires. The car felt like it would hesitate, and fell like if I was riding the breaks. Just felt heavy like if I was towing a load.
Below are some fresh shots of my fuel trims. It's still on a fresh ECU reset I haven't drove around yet. I'm still waiting on my bank 1 sensor to arrive tomorrow. So I'll have to pull the battery again to replace. The ones with ignition above 30 I'm holding the RPMs at 2k vs the other lower ones it's at idle. Coming up from a cold start.
Does your scanner do knock detection? I know a faulty knock sensor would not cause your gauge related fluctuation but that is some strange stuff. I ask about knock detection as gas quality plays a huge factor in peak MPG as any degradation causes reduction in ignition advance and subsequent poor mpg.
So basically you're seeing a 2 to 3 mpg drop for the same daily passage? What about temperature drop?
I've only had the 350 for one full winter and the cooler temps dropped it 1 full mpg or more. Our crap gas is the same blend all year so I don't think it's that. More the high idle below 38°F and length of time to get to operating temp.
I'm sure you checked brake drag and tire pressure. Sounds like you stand down until new sensor is in and see what happens.
FWIW LTFT are little to go on with a blank slate clean start battery disconnect. Get it out on the highway at different loads and rpms and then pull FT data.
Old school the egr used to create trim imbalances from bank to bank but we don't have that here. Keep throwing out details, we'll figure something out...
My scanner doesn't do Knock detection. It's an older model, but it comes in handy. I normally fill up on Exxon 93, but I've used Shell, Chevron. I was still getting crappy milage. I've been using Chevron for a few months now. After the new sensor is in place. I'll switch it back to Exxon as the station I use sees more traffic than the Chevron station near my home. So I'm assuming it has fresh inventory always. Yes I always check my tire pressure once a week or so. The brakes are normal they are working as they should. I recommend the Raybesto hybrid pads over the Akebono.
Ok so last night , and this morning I put 60 miles total. With just bank 2 S1 changed. The car pulled a little better than it did a few days ago. Even this morning it's colder out, and it's never pulled this hard entering the freeway, and lane changing. I had a smile on my face . It's too early to tell though so I'll keep my hopes down. Below are some shots I did while out last night. I did multiple hard pulls I've yet to smell raw fuel along with hard pulls this morning. Once I've got both new sensors installed. I'll update this post after letting the ECU run it's course.
^ So those are live data snapshots? Not averages or something like that?
Do you have torque pro where you can export a file a look at calculated load, rpm, ignition advance?
The reason I ask is the advance values look low.
Also no LTFT is being used when pinned. LTFT comes from near steady state loading like was suggested above.
When you pin it, it basically just looks at the fuel, ignition, air maps pulls a values from those maps for fueling. Where as if you pulled a hill in 4th and the rpms stayed say 4 to 5k with a near constant load, that's *A* condition where the ltft are created.
Yes I took those at different speeds I was driving around at. I don't have torque pro. I'm still looking for a good obd II Bluetooth adapter for CAN. I can do a record on this scanner drive cycle it should be the same right?
I finally got the new B1 S1, and went a filled up a fresh tank Exxon 93.
Putting about a 70 mile round trip. Countless hard pulls, and spirited driving. Basically I got Elephantiasis in my right foot.
My mileage seems to be where I used to be. I'm feeling confident it is normal now. Even on a fresh ECU reset. It's a bit chilly out now so even then. I'm getting the same numbers as I'm used to seeing. Milage readings seem to stabilized to normal. I should see better results as the ECU learns some more.
Update #2 11/3/18
Drove to my family's home out 40 miles in the country side this morning. Still getting good results as the temps are around 55F this morning. One thing I did notice is my operating temperature is coming up faster. Day past when my MPG meter would fluctuate. It seemed my coolant temp on the dash would take forever to reach the regular mark of 1/2 way. Even at upper 78F-90F it would take a few miles to get there. This morning at cold temps it reached 1/4 mark a few hundred feet from my home. Definitely now the car feels good.
I finally got the new B1 S1, and went a filled up a fresh tank Exxon 93.
Putting about a 70 mile round trip. Countless hard pulls, and spirited driving. Basically I got Elephantiasis in my right foot.
My mileage seems to be where I used to be. I'm feeling confident it is normal now. Even on a fresh ECU reset. It's a bit chilly out now so even then. I'm getting the same numbers as I'm used to seeing. Milage readings seem to stabilized to normal. I should see better results as the ECU learns some more.
Update #2 11/3/18
Drove to my family's home out 40 miles in the country side this morning. Still getting good results as the temps are around 55F this morning. One thing I did notice is my operating temperature is coming up faster. Day past when my MPG meter would fluctuate. It seemed my coolant temp on the dash would take forever to reach the regular mark of 1/2 way. Even at upper 78F-90F it would take a few miles to get there. This morning at cold temps it reached 1/4 mark a few hundred feet from my home. Definitely now the car feels good.
Sounds like good news! This bad but I just haven't looked it up, are these wideband o2 sensors?
Other than my old cast iron V8's w carbs, I've never had an engine take as long as this to warm to operating temp. Much less idle down in a short period.
Its at 72k mi... S1 responses look good at the moment. But it makes you wonder....
When temps drop to twenties it just wants to run everything over for the first 3 to 4 miles which flat or down hill so little work is required. Maybe I should drag an anchor! lol
Sounds like good news! This bad but I just haven't looked it up, are these wideband o2 sensors?
Other than my old cast iron V8's w carbs, I've never had an engine take as long as this to warm to operating temp. Much less idle down in a short period.
Its at 72k mi... S1 responses look good at the moment. But it makes you wonder....
When temps drop to twenties it just wants to run everything over for the first 3 to 4 miles which flat or down hill so little work is required. Maybe I should drag an anchor! lol
Sounds like good news! This bad but I just haven't looked it up, are these wideband o2 sensors?
Other than my old cast iron V8's w carbs, I've never had an engine take as long as this to warm to operating temp. Much less idle down in a short period.
Its at 72k mi... S1 responses look good at the moment. But it makes you wonder....
When temps drop to twenties it just wants to run everything over for the first 3 to 4 miles which flat or down hill so little work is required. Maybe I should drag an anchor! lol
11-01-18, 09:18 AM
Upstream O2's DIY CONDENSED
I recommend the Raybesto hybrid pads over the Akebono.
. It's too early to tell though so I'll keep my hopes down. Below are some shots I did while out last night. I did multiple hard pulls I've yet to smell raw fuel along with hard pulls this morning. Once I've got both new sensors installed. I'll update this post after letting the ECU run it's course.
