O2 Sensor Change

Mr Bill · February 17, 2004

Hi, I have a '96 ES300 with just over 100k miles and want to change the O2 sensor. I understand from otyher posts here changing the sensor is easy - but do I need to "reset the ECM" or anything like that - or do I simply change the sensor?

TIA, Mr Bill :cheers:

ajay95 · February 17, 2004

Its very easy, once you are done changing the O2 sensor, just unplug the battery for about 5-10 minutes and that will reset the ECM.... Good luck

steviej · February 18, 2004

are you changing the O2 sensor: 1.) just to change it or 2.) cause you got a faulty one and the CEL is being triggered?

If it is 1.) then there is no reason to reset because the ECM doesn't know anything is wrong.

If it is 2.) then replacement with a functioning O2 sensor should remove the faulty code from the ECM (it will remain in memory but the CEL will go out) when the car is turned back on.

I don't think you have to disconnect the battery. Of course that will work, but you will have to reprogram all your presets (radio stations, seat position, mirror positions, etc).

If your ultimate aim is to just reset the ECM so that it will relearn your driving with a fresh O2 sensor, it may be easier just to pull the engine fuse and not disconnect the battery, saves all the reprogramming of the radio, seats and mirrors.

steviej

col_panic · February 19, 2004

My '95 es300 has a P0135 code that says the 02 sensor at bank one, sensor one is bad. The part is $138 and I am picking it up today, but I am not sure if it is the one at the radiator or the firewall. Does anyone know?

SKperformance · February 19, 2004

firewall

ajay95 · February 19, 2004

Its the one by firewall. I was told by lexus that its a good idea to change them both at the same time. I ordered the part from www.irontoad.com for about $101 a piece lexus parts and changed them my self in 30 minutes. Lexus wanted Total of $600 labor charge to change both....

col_panic · February 19, 2004

thanks. i'm just going to change the one at first due to the part cost and buy it from the dealer so i can do it saturday morning. will report with results.

Update:

i swapped it out last night and noticed that the sluggishness of the engine disappeared afterward. the whole job probably took 10 minutes after the engine cooled down. the only part that was not simple was that the wire harness does not have much room to rotate around with the sensor when un/!Removed! and i had to be careful not to damage the wires.

as for the check engine light, i only idled for about 30 seconds after restarting the car and the light had not gone out, so i cleared the code with the obd ii reader.