Hi
im geting p0125 and im thinking these ppl im takin my car to dnt know anything long story short

Changed the temp sensor ( not new )
Changed the coolant and radiator cap
Changed the valve cover gaskets ( slight leak )
Swap the bank 1 and 2 o2 sesnors didnt go off so we put the same ones bk in

I spent almosts 350dollars for random checkups and random parts

Whenevrr i take the car on the highway thats when the light comes on

 

Bump

so what i done so far is swapped all 4 of the o2 sensor n i notice the cel light doesnt pop up on the high way and fuel filter changed

 

You didnt get any hits because you posted in the wrong forum.

 

I had this exact same code on my 97 Ls, I replaced the thermostat with a OEM thermostat and the code went away.

 

Why were you guys messing with oxygen sensors when the CEL code is referring to coolant temp? From previous experience this is most likely caused by thermostat (90% chance) or coolant temp sensor.

 

that code can fool you... I had it on my 99 and done all the coolant stuff then took it to a dealer..
Got it fixed, autozone was 1st level, went to Davenport Lexus and they read at lower level said bank 1 02 sensor heater was SLOW TO CLOSE because of being oil soaked. replaced VC gskts and 02 sensor, no more P0125 CEL light.

they also had to clean the wiring connector to make it completely dry

akswagga try this and let us know

 

I got this code from a faulty O2 Sensor. It was the sensor closest to the engine on the driver's side. Replaced once last year with a no-name brand and kept replacing other items (thermostat, coolant temp sensor), and finally bit the bullet and replaced this O2 sensor again with a Denso and the code went away.

 

Kinda funny all the fixes where an O2 sensor, when the code and the main thing that sets the code is the engine coolant temperature sensor. If its not seeing the operating temp then its not letting it go closed loop. So if its not closed loop then the O2 sensors are simply put not doing a thing. If an O2 sensor is setting the code then there must be a problem with the ecu. I'm with SonicC on this one.
Please explain the reasoning why an O2 sensor problem would set the code? Then read the Lexus service information about what sets it. I don't have a manual for that year so I'm going off of other info I found for Toyota.

http://us.lexusownersclub.com/forums...el-code-p0125/
Well if the O2 sensor really does set the code then the description of the code is wrong, or the ecu is programmed wrong which is it?

 

About half way scroll down, there is mention of the code not identified correctly and being more of a "NOT GOING INTO CLOSED LOOP" rather than coolant temp not allowing it, though coolant temp would not allow it.
And this only makes sense since O2 problems are associated with the code. I would really like to know whats going on with P0125 from Lexus.

http://autoforums.carjunky.com/Autom...rol%29_P76665/

 

write them a letter

 

http://www.toyotanation.com/forum/13...hermostat.html

Undocumented P0125, so I guess others have searched out this mess too. P0125 is likely anything that keeps it out of closed loop. Must be a Toyota thing, it says it confuses lots of techs.

Makes sense to undocument a DTC that way no other repair outfit can jump on the problem. Forces you to take it to the dealer. Nice.

 

Thats exactly what i had VC had a slight leak fixed that and the thermostatt changed radiator cap also cause there was lose of persure and swapped the ETC sensor like every one says its just that when its not
http://engine-codes.com/p0125_toyota.html

Ill do that billy which connecters .? The o2 sensor ones ..??
Im thinking I'll erase the code cause what i done is just unplug the battery n let the ecm reset

ill try to also borrow my buddy Bluetooth ODB reader hopefully that thing can erase it


Edit i reported your post by mistake lol

 

the 02 sensor plug was oil soaked and they dried it with something (??) but it came out dry.. and they used their ODB to clear the code..

 

My o2 sensor i didnt check but i had vc leakage and so i asked da guy to swap all 4 o2 sensor from another ls400 to mine n it worked fine there is no check engine light but after a day or two it pops back up maybe cause we didnt rest the ecu ?

Im thinking thats why the Cl keeps poping bk up maybe it needs to be
erased frist ?

its taking a day for the check engine light to come bk unlike before only on the high way it will come on but now days

 

Now cel with p0156
so were is bank 2 sensor 2 ? Ill change that