97 LS400 O2 Sensor Replacement Tips
10-29-05, 07:04 PM
#1
Intermediate
Thread Starter
97 LS400 O2 Sensor Replacement Tips
I got my first CHECK ENGINE light on my LS400 about 2 weeks ago, with a tad over 119K miles on the clock. Other than a faulty starter at 89K miles, this car has been dead nuts reliable, and even then it never left me stranded. There was no noticeable difference in performance once the CE light came on, the car ran as smooth as usual. But I'm not the type to drive around with a CE light on as I know there's a sensor bad *somewhere*.
I did a few searches here on Club Lexus and it seems the most common cause for CE light is faulty O2 sensors. I was hoping for that as the worst case, or a loose gas cap best case
So I went a local Autozone to buy an OBDII Code Scanner, but they actually offered to pull the code(s) for free with their own scanner...so, I saved $100 there. The Code was P0135, which is driver side front O2 sensor. Autozone wanted $158/ per sensor for the OEM replacements. I knew that was high from what I've read here, so I called my normal Lexus parts source, Carson Toyota, and with my Club Lexus discount I paid $118 ea. I replaced both front sensors, not just the bad one because A) The pass side sensor is also about to fail due to mileage and B) I'd like to pick up a few MPG with two new sensors vs one.
As usual Carson Toyota came through for me....they even shipped me the sensor overnight on Thursday from So. Cal to Nor Cal so I'd have it for today since they had to order one in.
This morning I put the car up on jackstands to change out the sensors. Turns out I needed an oxygen sensor socket, there was just no way to get a 22mm wrench on either of the front sensors. The tutorial I found on the web was for a '90-'94, and those O2 sensors can be removed with a 22mm wrench. Not the Gen IIs. So I take one of my other cars to the closest Kragen Auto Parts and buy the $16 univeral 1/2" drive hardened O2 sensor socket.
The driver side sensor breaks loose after a pretty good effort, and it takes all of 5 min. to replace, tighten, and reconnect.
The pass. side (which was the 'good' sensor) decides to put up a fight, and the O2 sensor socket slips due to a slightly off angle and starts to strip the sensor....it's not budging. I tried this twice and it's starting to look ugly as the socket slips again. The sensor is really starting to strip.
In a brief moment of clarity, I fired up my compressor and broke out the 1/2" impact gun. I had to use an extension to get access with the gun, but after 2 shots with the HD impact the sensor breaks loose...as it continues to strip. Fortunately, I got it out OK as the impact actually jammed the sensor into the socked pretty good. Reinstallation took all of 5 min
.
I then disconnected the battery and pulled the 20 amp EFI fuse to erase the codes. I've driven the car all day and so far no more Check Engine Light. I'm probably going to test the bad sensor tomorrow to confirm that it's truly defective.
So, here's my advice for those who are changing the front O2 sensors on '95-97 LS400s...
1)You *will* need a 22mm O2 sensor socket, a standard wrench will NOT work on the front O2 sensors.
2)The original sensors are going to be very TIGHT, I recommend hitting them with a shot of PB Blaster solvent and letting them soak for a few hours (which is what I should have done) or using an impact wrench to loosen the sensor. A stripped sensor will ruin your day, if not the entire weekend
.
That's about it, total cost to replace both front sensors with Toyota OEM parts was $258 for the sensors (yah, that's pricey) and $16 for the O2 sensor socket. This assumes one has a toolbox full of tools including compressor and air tools.
I did a few searches here on Club Lexus and it seems the most common cause for CE light is faulty O2 sensors. I was hoping for that as the worst case, or a loose gas cap best case
So I went a local Autozone to buy an OBDII Code Scanner, but they actually offered to pull the code(s) for free with their own scanner...so, I saved $100 there. The Code was P0135, which is driver side front O2 sensor. Autozone wanted $158/ per sensor for the OEM replacements. I knew that was high from what I've read here, so I called my normal Lexus parts source, Carson Toyota, and with my Club Lexus discount I paid $118 ea. I replaced both front sensors, not just the bad one because A) The pass side sensor is also about to fail due to mileage and B) I'd like to pick up a few MPG with two new sensors vs one.
As usual Carson Toyota came through for me....they even shipped me the sensor overnight on Thursday from So. Cal to Nor Cal so I'd have it for today since they had to order one in.
This morning I put the car up on jackstands to change out the sensors. Turns out I needed an oxygen sensor socket, there was just no way to get a 22mm wrench on either of the front sensors. The tutorial I found on the web was for a '90-'94, and those O2 sensors can be removed with a 22mm wrench. Not the Gen IIs. So I take one of my other cars to the closest Kragen Auto Parts and buy the $16 univeral 1/2" drive hardened O2 sensor socket.
The driver side sensor breaks loose after a pretty good effort, and it takes all of 5 min. to replace, tighten, and reconnect.
The pass. side (which was the 'good' sensor) decides to put up a fight, and the O2 sensor socket slips due to a slightly off angle and starts to strip the sensor....it's not budging. I tried this twice and it's starting to look ugly as the socket slips again. The sensor is really starting to strip.
In a brief moment of clarity, I fired up my compressor and broke out the 1/2" impact gun. I had to use an extension to get access with the gun, but after 2 shots with the HD impact the sensor breaks loose...as it continues to strip. Fortunately, I got it out OK as the impact actually jammed the sensor into the socked pretty good. Reinstallation took all of 5 min
.I then disconnected the battery and pulled the 20 amp EFI fuse to erase the codes. I've driven the car all day and so far no more Check Engine Light. I'm probably going to test the bad sensor tomorrow to confirm that it's truly defective.
So, here's my advice for those who are changing the front O2 sensors on '95-97 LS400s...
1)You *will* need a 22mm O2 sensor socket, a standard wrench will NOT work on the front O2 sensors.
2)The original sensors are going to be very TIGHT, I recommend hitting them with a shot of PB Blaster solvent and letting them soak for a few hours (which is what I should have done) or using an impact wrench to loosen the sensor. A stripped sensor will ruin your day, if not the entire weekend
. That's about it, total cost to replace both front sensors with Toyota OEM parts was $258 for the sensors (yah, that's pricey) and $16 for the O2 sensor socket. This assumes one has a toolbox full of tools including compressor and air tools.
12-12-11, 05:30 PM
#5
Intermediate
Thread Starter
Bringing this thread back to life.....I just diagnosed code P0135 on my 2nd '97 LS 400 Coach Ed. Same exact sensor, only this one lived to 128K miles vs. 119K on my old car.
12-13-11, 04:52 AM
#7
Driver School Candidate
I got my first CHECK ENGINE light on my LS400 about 2 weeks ago, with a tad over 119K miles on the clock. Other than a faulty starter at 89K miles, this car has been dead nuts reliable, and even then it never left me stranded. There was no noticeable difference in performance once the CE light came on, the car ran as smooth as usual. But I'm not the type to drive around with a CE light on as I know there's a sensor bad *somewhere*.
I did a few searches here on Club Lexus and it seems the most common cause for CE light is faulty O2 sensors. I was hoping for that as the worst case, or a loose gas cap best case
So I went a local Autozone to buy an OBDII Code Scanner, but they actually offered to pull the code(s) for free with their own scanner...so, I saved $100 there. The Code was P0135, which is driver side front O2 sensor. Autozone wanted $158/ per sensor for the OEM replacements. I knew that was high from what I've read here, so I called my normal Lexus parts source, Carson Toyota, and with my Club Lexus discount I paid $118 ea. I replaced both front sensors, not just the bad one because A) The pass side sensor is also about to fail due to mileage and B) I'd like to pick up a few MPG with two new sensors vs one.
As usual Carson Toyota came through for me....they even shipped me the sensor overnight on Thursday from So. Cal to Nor Cal so I'd have it for today since they had to order one in.
This morning I put the car up on jackstands to change out the sensors. Turns out I needed an oxygen sensor socket, there was just no way to get a 22mm wrench on either of the front sensors. The tutorial I found on the web was for a '90-'94, and those O2 sensors can be removed with a 22mm wrench. Not the Gen IIs. So I take one of my other cars to the closest Kragen Auto Parts and buy the $16 univeral 1/2" drive hardened O2 sensor socket.
The driver side sensor breaks loose after a pretty good effort, and it takes all of 5 min. to replace, tighten, and reconnect.
The pass. side (which was the 'good' sensor) decides to put up a fight, and the O2 sensor socket slips due to a slightly off angle and starts to strip the sensor....it's not budging. I tried this twice and it's starting to look ugly as the socket slips again. The sensor is really starting to strip.
In a brief moment of clarity, I fired up my compressor and broke out the 1/2" impact gun. I had to use an extension to get access with the gun, but after 2 shots with the HD impact the sensor breaks loose...as it continues to strip. Fortunately, I got it out OK as the impact actually jammed the sensor into the socked pretty good. Reinstallation took all of 5 min.
I then disconnected the battery and pulled the 20 amp EFI fuse to erase the codes. I've driven the car all day and so far no more Check Engine Light. I'm probably going to test the bad sensor tomorrow to confirm that it's truly defective.
So, here's my advice for those who are changing the front O2 sensors on '95-97 LS400s...
1)You *will* need a 22mm O2 sensor socket, a standard wrench will NOT work on the front O2 sensors.
2)The original sensors are going to be very TIGHT, I recommend hitting them with a shot of PB Blaster solvent and letting them soak for a few hours (which is what I should have done) or using an impact wrench to loosen the sensor. A stripped sensor will ruin your day, if not the entire weekend .
That's about it, total cost to replace both front sensors with Toyota OEM parts was $258 for the sensors (yah, that's pricey) and $16 for the O2 sensor socket. This assumes one has a toolbox full of tools including compressor and air tools.
I did a few searches here on Club Lexus and it seems the most common cause for CE light is faulty O2 sensors. I was hoping for that as the worst case, or a loose gas cap best case
So I went a local Autozone to buy an OBDII Code Scanner, but they actually offered to pull the code(s) for free with their own scanner...so, I saved $100 there. The Code was P0135, which is driver side front O2 sensor. Autozone wanted $158/ per sensor for the OEM replacements. I knew that was high from what I've read here, so I called my normal Lexus parts source, Carson Toyota, and with my Club Lexus discount I paid $118 ea. I replaced both front sensors, not just the bad one because A) The pass side sensor is also about to fail due to mileage and B) I'd like to pick up a few MPG with two new sensors vs one.
As usual Carson Toyota came through for me....they even shipped me the sensor overnight on Thursday from So. Cal to Nor Cal so I'd have it for today since they had to order one in.
This morning I put the car up on jackstands to change out the sensors. Turns out I needed an oxygen sensor socket, there was just no way to get a 22mm wrench on either of the front sensors. The tutorial I found on the web was for a '90-'94, and those O2 sensors can be removed with a 22mm wrench. Not the Gen IIs. So I take one of my other cars to the closest Kragen Auto Parts and buy the $16 univeral 1/2" drive hardened O2 sensor socket.
The driver side sensor breaks loose after a pretty good effort, and it takes all of 5 min. to replace, tighten, and reconnect.
The pass. side (which was the 'good' sensor) decides to put up a fight, and the O2 sensor socket slips due to a slightly off angle and starts to strip the sensor....it's not budging. I tried this twice and it's starting to look ugly as the socket slips again. The sensor is really starting to strip.
In a brief moment of clarity, I fired up my compressor and broke out the 1/2" impact gun. I had to use an extension to get access with the gun, but after 2 shots with the HD impact the sensor breaks loose...as it continues to strip. Fortunately, I got it out OK as the impact actually jammed the sensor into the socked pretty good. Reinstallation took all of 5 min
.I then disconnected the battery and pulled the 20 amp EFI fuse to erase the codes. I've driven the car all day and so far no more Check Engine Light. I'm probably going to test the bad sensor tomorrow to confirm that it's truly defective.
So, here's my advice for those who are changing the front O2 sensors on '95-97 LS400s...
1)You *will* need a 22mm O2 sensor socket, a standard wrench will NOT work on the front O2 sensors.
2)The original sensors are going to be very TIGHT, I recommend hitting them with a shot of PB Blaster solvent and letting them soak for a few hours (which is what I should have done) or using an impact wrench to loosen the sensor. A stripped sensor will ruin your day, if not the entire weekend
. That's about it, total cost to replace both front sensors with Toyota OEM parts was $258 for the sensors (yah, that's pricey) and $16 for the O2 sensor socket. This assumes one has a toolbox full of tools including compressor and air tools.
I've been driving around for the past month with the cel on It's the driver side 02 for me.
Did you notice any difference when you replaced yours??
I guess thats why I haven't done mine yet really no need right??
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12-13-11, 06:36 AM
#8
I just replaced both of mine, on my 96, one in November with code 135, with in a week came back on with code 150 and yesterday replaced it. the car ran no different before or after, but the light bugged me.
mine has 186k on it.
mine has 186k on it.
Last edited by billydpowe; 12-13-11 at 06:42 AM.
12-13-11, 08:21 AM
#9
Intermediate
Thread Starter
There has been no change or difference in performance or gas mileage. I passed CA smog 6mo ago, so no worries there either. However, it's gotta be changed, so I'll knock it out over the weekend.
12-26-11, 12:55 PM
#10
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Join Date: Dec 2011
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I got my first CHECK ENGINE light on my LS400 about 2 weeks ago, with a tad over 119K miles on the clock. Other than a faulty starter at 89K miles, this car has been dead nuts reliable, and even then it never left me stranded. There was no noticeable difference in performance once the CE light came on, the car ran as smooth as usual. But I'm not the type to drive around with a CE light on as I know there's a sensor bad *somewhere*.
I did a few searches here on Club Lexus and it seems the most common cause for CE light is faulty O2 sensors. I was hoping for that as the worst case, or a loose gas cap best case
So I went a local Autozone to buy an OBDII Code Scanner, but they actually offered to pull the code(s) for free with their own scanner...so, I saved $100 there. The Code was P0135, which is driver side front O2 sensor. Autozone wanted $158/ per sensor for the OEM replacements. I knew that was high from what I've read here, so I called my normal Lexus parts source, Carson Toyota, and with my Club Lexus discount I paid $118 ea. I replaced both front sensors, not just the bad one because A) The pass side sensor is also about to fail due to mileage and B) I'd like to pick up a few MPG with two new sensors vs one.
As usual Carson Toyota came through for me....they even shipped me the sensor overnight on Thursday from So. Cal to Nor Cal so I'd have it for today since they had to order one in.
This morning I put the car up on jackstands to change out the sensors. Turns out I needed an oxygen sensor socket, there was just no way to get a 22mm wrench on either of the front sensors. The tutorial I found on the web was for a '90-'94, and those O2 sensors can be removed with a 22mm wrench. Not the Gen IIs. So I take one of my other cars to the closest Kragen Auto Parts and buy the $16 univeral 1/2" drive hardened O2 sensor socket.
The driver side sensor breaks loose after a pretty good effort, and it takes all of 5 min. to replace, tighten, and reconnect.
The pass. side (which was the 'good' sensor) decides to put up a fight, and the O2 sensor socket slips due to a slightly off angle and starts to strip the sensor....it's not budging. I tried this twice and it's starting to look ugly as the socket slips again. The sensor is really starting to strip.
In a brief moment of clarity, I fired up my compressor and broke out the 1/2" impact gun. I had to use an extension to get access with the gun, but after 2 shots with the HD impact the sensor breaks loose...as it continues to strip. Fortunately, I got it out OK as the impact actually jammed the sensor into the socked pretty good. Reinstallation took all of 5 min.
I then disconnected the battery and pulled the 20 amp EFI fuse to erase the codes. I've driven the car all day and so far no more Check Engine Light. I'm probably going to test the bad sensor tomorrow to confirm that it's truly defective.
So, here's my advice for those who are changing the front O2 sensors on '95-97 LS400s...
1)You *will* need a 22mm O2 sensor socket, a standard wrench will NOT work on the front O2 sensors.
2)The original sensors are going to be very TIGHT, I recommend hitting them with a shot of PB Blaster solvent and letting them soak for a few hours (which is what I should have done) or using an impact wrench to loosen the sensor. A stripped sensor will ruin your day, if not the entire weekend .
That's about it, total cost to replace both front sensors with Toyota OEM parts was $258 for the sensors (yah, that's pricey) and $16 for the O2 sensor socket. This assumes one has a toolbox full of tools including compressor and air tools.
I did a few searches here on Club Lexus and it seems the most common cause for CE light is faulty O2 sensors. I was hoping for that as the worst case, or a loose gas cap best case
So I went a local Autozone to buy an OBDII Code Scanner, but they actually offered to pull the code(s) for free with their own scanner...so, I saved $100 there. The Code was P0135, which is driver side front O2 sensor. Autozone wanted $158/ per sensor for the OEM replacements. I knew that was high from what I've read here, so I called my normal Lexus parts source, Carson Toyota, and with my Club Lexus discount I paid $118 ea. I replaced both front sensors, not just the bad one because A) The pass side sensor is also about to fail due to mileage and B) I'd like to pick up a few MPG with two new sensors vs one.
As usual Carson Toyota came through for me....they even shipped me the sensor overnight on Thursday from So. Cal to Nor Cal so I'd have it for today since they had to order one in.
This morning I put the car up on jackstands to change out the sensors. Turns out I needed an oxygen sensor socket, there was just no way to get a 22mm wrench on either of the front sensors. The tutorial I found on the web was for a '90-'94, and those O2 sensors can be removed with a 22mm wrench. Not the Gen IIs. So I take one of my other cars to the closest Kragen Auto Parts and buy the $16 univeral 1/2" drive hardened O2 sensor socket.
The driver side sensor breaks loose after a pretty good effort, and it takes all of 5 min. to replace, tighten, and reconnect.
The pass. side (which was the 'good' sensor) decides to put up a fight, and the O2 sensor socket slips due to a slightly off angle and starts to strip the sensor....it's not budging. I tried this twice and it's starting to look ugly as the socket slips again. The sensor is really starting to strip.
In a brief moment of clarity, I fired up my compressor and broke out the 1/2" impact gun. I had to use an extension to get access with the gun, but after 2 shots with the HD impact the sensor breaks loose...as it continues to strip. Fortunately, I got it out OK as the impact actually jammed the sensor into the socked pretty good. Reinstallation took all of 5 min
.I then disconnected the battery and pulled the 20 amp EFI fuse to erase the codes. I've driven the car all day and so far no more Check Engine Light. I'm probably going to test the bad sensor tomorrow to confirm that it's truly defective.
So, here's my advice for those who are changing the front O2 sensors on '95-97 LS400s...
1)You *will* need a 22mm O2 sensor socket, a standard wrench will NOT work on the front O2 sensors.
2)The original sensors are going to be very TIGHT, I recommend hitting them with a shot of PB Blaster solvent and letting them soak for a few hours (which is what I should have done) or using an impact wrench to loosen the sensor. A stripped sensor will ruin your day, if not the entire weekend
. That's about it, total cost to replace both front sensors with Toyota OEM parts was $258 for the sensors (yah, that's pricey) and $16 for the O2 sensor socket. This assumes one has a toolbox full of tools including compressor and air tools.
I have a question
Is the check engine light on necessary for the o 2 sensors to be out of order?
Can the sensors break down yet the ce light id still off?
And if u have checked ur mpg
Did it improve after chaging the sensors?
12-26-11, 04:29 PM
#11
never heard of it....
havent checked mpg, but I always know how many miles I have traveled on the tank, and after filling up, I mentally divide out my mpg to make sure the first number is always a 2, from there on I dont care, I know it is good. (plus I have always been good at numbers)
good luck on yours..
havent checked mpg, but I always know how many miles I have traveled on the tank, and after filling up, I mentally divide out my mpg to make sure the first number is always a 2, from there on I dont care, I know it is good. (plus I have always been good at numbers)
good luck on yours..
01-02-12, 01:49 AM
#12
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never heard of it....
havent checked mpg, but I always know how many miles I have traveled on the tank, and after filling up, I mentally divide out my mpg to make sure the first number is always a 2, from there on I dont care, I know it is good. (plus I have always been good at numbers)
good luck on yours..
havent checked mpg, but I always know how many miles I have traveled on the tank, and after filling up, I mentally divide out my mpg to make sure the first number is always a 2, from there on I dont care, I know it is good. (plus I have always been good at numbers)
good luck on yours..
I code csanned the car few days ago and apart from an old transmission torbine code it all fine
My mechanic said the torbine is fine and even though it has nothing to do with fuel consumption
I asked him about the engine coolant temp sensor since it was mentioned in other threads and he scanned it and said it was ok and cannt be broken with no codes so he did not advise to change it
Actually in the scan the car is fine from a to z
I asked him whether the injectors need to be serviced he said it will give them a wider new caliber which means more fuel and the better is to change the and try but they are too pricy to worth a shot
01-02-12, 03:00 AM
#13
Mine is doing 18 mpg at it's best
I code csanned the car few days ago and apart from an old transmission torbine code it all fine
My mechanic said the torbine is fine and even though it has nothing to do with fuel consumption
I asked him about the engine coolant temp sensor since it was mentioned in other threads and he scanned it and said it was ok and cannt be broken with no codes so he did not advise to change it
Actually in the scan the car is fine from a to z
I asked him whether the injectors need to be serviced he said it will give them a wider new caliber which means more fuel and the better is to change the and try but they are too pricy to worth a shot
I code csanned the car few days ago and apart from an old transmission torbine code it all fine
My mechanic said the torbine is fine and even though it has nothing to do with fuel consumption
I asked him about the engine coolant temp sensor since it was mentioned in other threads and he scanned it and said it was ok and cannt be broken with no codes so he did not advise to change it
Actually in the scan the car is fine from a to z
I asked him whether the injectors need to be serviced he said it will give them a wider new caliber which means more fuel and the better is to change the and try but they are too pricy to worth a shot
01-18-12, 07:51 PM
#15
Ill add my question here instead of starting a new thread since it specifically a P0135 code.
For 2 months I've been running a 5zigen Mega GT axle back... Recently I decided to add more grunt so I had the center section modified. From the collector up front I deleted the center muffler & added a 2.5" pipe from the collector right down the middle & flanged it before it splits up & routes under the rear seats. I got the noise I wanted but later that night I get a CEL & the P0135 code.
Is the extra exhaust flow setting this off ? Is there any reasonable answer to why it would suddenly show up after modification ? My 99' has 60k miles & I assumed the sensor is original.
For 2 months I've been running a 5zigen Mega GT axle back... Recently I decided to add more grunt so I had the center section modified. From the collector up front I deleted the center muffler & added a 2.5" pipe from the collector right down the middle & flanged it before it splits up & routes under the rear seats. I got the noise I wanted but later that night I get a CEL & the P0135 code.
Is the extra exhaust flow setting this off ? Is there any reasonable answer to why it would suddenly show up after modification ? My 99' has 60k miles & I assumed the sensor is original.
