02' GS300, CEL help P0125
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Lexus Test Driver
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Joined: Apr 2008
Posts: 899
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From: New York - Queens
I had a friend check the sensors for me and he said the bank2 sensor1 is not getting any power at all. its getting late and did nto get a chance top view the fuses yet. but what could be the cause of the problem? short in the wires? ecm? bad harness? thanks
Last edited by Mike813; Dec 3, 2008 at 01:49 PM.
Thread Starter
Lexus Test Driver
iTrader: (5)
Joined: Apr 2008
Posts: 899
Likes: 2
From: New York - Queens
found my answer, turned out to be a wire in bank2 sensor 1 that was split. everytime i hit a bump or something the wire would disconnect with the other end and throw the code. thats why travelling @ 1-30mph it didnt trigger till i hit a bump. and it did not trigger under diagnostics during the idle for 100 sec, go 30mph and hold etc etc. Thanks again for everyones help, and apologies for the multi thread.
booooooooYAHHHHHHHHH
o2 sensor!
It's never as easy as it seems like it will be...
Had you followed others instructions, you woulda wasted money on coolant temp sensors and all kinds of other stuff... I've been doing diagnostics on cars long enough to know that only about 50% of the time is it ever the easy obvious fix...
o2 sensor!
It's never as easy as it seems like it will be...
Had you followed others instructions, you woulda wasted money on coolant temp sensors and all kinds of other stuff... I've been doing diagnostics on cars long enough to know that only about 50% of the time is it ever the easy obvious fix...
booooooooYAHHHHHHHHH
o2 sensor!
It's never as easy as it seems like it will be...
Had you followed others instructions, you woulda wasted money on coolant temp sensors and all kinds of other stuff... I've been doing diagnostics on cars long enough to know that only about 50% of the time is it ever the easy obvious fix...
o2 sensor!
It's never as easy as it seems like it will be...
Had you followed others instructions, you woulda wasted money on coolant temp sensors and all kinds of other stuff... I've been doing diagnostics on cars long enough to know that only about 50% of the time is it ever the easy obvious fix...
Thread Starter
Lexus Test Driver
iTrader: (5)
Joined: Apr 2008
Posts: 899
Likes: 2
From: New York - Queens
ya, thanks again! the car feels back to normal now... a few weeks back it felt like it was running on 4 cyl only, when i accelerate the engine would sound like its knocking and all that good stuff, now its smooth sailing again!
Driver School Candidate
Joined: Feb 2015
Posts: 2
Likes: 0
From: California
Help , old post bump
I have the same problem code (p0125)and I changed both of the O2 sensors , the termostat and the coolant temp sensor but my check engine still came back on, what else could it be ? Thanks in advance .
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I've actually heard of the GS's having issues with frozen o2 sensors in the manifolds... PB Blaster is your friend... use a lot of it... multiple times...
Easy way to test o2 sensors - should be a 4 wire sensor - one should fluctuate between .1 and .9 volts, and two others should have resistance between them, which will depend on the temperature they are tested at - typically 10 ohms or more between the two... test for resistance without the sensor plugged in, test for voltage with the car running... their test is for after cat sensors... Sensor 2 is a downstream sensor and shouldn't cause your problem - most likely it's a Sensor 1 (bank 1 or 2)... Bank 1 is one side of the engine, bank 2 is the other side, sensor 1 is before the catalytic convert, sensor 2 is after the catalytic converter...
anyways, watched on a voltmeter, you should see a sweep that ranges from less than .5 volts to more than .5 volts... typically it'll be like .2 volts then .8 volts, then .2 volts, then .8 volts... it'll cycle back and forth once or twice a second...
Easy way to test o2 sensors - should be a 4 wire sensor - one should fluctuate between .1 and .9 volts, and two others should have resistance between them, which will depend on the temperature they are tested at - typically 10 ohms or more between the two... test for resistance without the sensor plugged in, test for voltage with the car running... their test is for after cat sensors... Sensor 2 is a downstream sensor and shouldn't cause your problem - most likely it's a Sensor 1 (bank 1 or 2)... Bank 1 is one side of the engine, bank 2 is the other side, sensor 1 is before the catalytic convert, sensor 2 is after the catalytic converter...
anyways, watched on a voltmeter, you should see a sweep that ranges from less than .5 volts to more than .5 volts... typically it'll be like .2 volts then .8 volts, then .2 volts, then .8 volts... it'll cycle back and forth once or twice a second...
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