For all that are interested here is the breakdown of my symptoms/cost/and things to know when checking on O2 sensor problems.


My check engine light came on along with my TRAC light (this combination of lights is telling you right off the start the your problem lies in the O2 sensors (which one is what im about to discuss)

I went to a foreign car specialist cause lexus wanted to take me for a money spending spree. My mechanic got error code 25 which means your exhaust is running lean (upstream airflow). For a complete list on all lexus error codes BELOW they are listed. Anyway upstream means the front sensors (MAIN SENSORS). Unfortunatley, there is no error code to tell you which sensor of the two MAINS has gone bad and you don't wanna replace one and have an old one (YOU WANNA REPLACE IN PAIRS). Each sensor from lexus was $145 ea/diag fee $80/$113 install fee.....total bill to replace just the front two MAIN O2 sensors was $483.00 (lexus was trying to tell me that if they replace the two MAINS then they have to replace the manifold cause they usually melt (get stuck) in there cause of the heat. This is Bull (that happens 1 in a million)....Since the replacment of the sensors my engine light has not come back on and I have noticed I'm not burning gas up as much as normal (cause the Front 2 sensors are the ones that interact with the engine the rear 2 just basically report errors if the cats are going bad mainly)......................


Hope this helped out there is also an error code

LEXUS ERROR CODES/WHAT THEY MEAN

ALL THE ERROR CODES FOR LEXUS AND WHAT THEY MEAN

1 Normal Condition.
2 Air Flow Meter signal.
3 Ignition signal.
4 Engine Coolant Temperature Sensor signal.
5 Oxygen Sensor.
6 RPM signal (Crank Angle Pulse).
7 Throttle Position Sensor signal.
8 Intake Air Temperature Sensor signal.
9 Vehicle Speed Sensor signal.
10 Starter signal.
11 Switch signal.
11 ECU/ECM.
12 Knock Control Sensor signal.
12 RPM signal.
13 Knock Control CPU (ECM).
13 RPM signal.
14 Turbocharger Pressure.
14 Ignition signal.
21 Oxygen Sensor.
22 Engine Coolant Temperature Sensor signal.
23 Intake Air Temperature Sensor signal.
24 Intake Air Temperature Sensor signal.
25 Air-Fuel Ratio Lean.
26 Air-Fuel Ratio Rich.
27 Sub Oxygen Sensor signal.
28 No. 2 Oxygen Sensor signal.
31 Air Flow Meter signal (Vacuum Sensor signal).
32 Air Flow Meter signal.
34 Turbocharger Pressure signal.
35 Turbocharger Pressure Sensor signal.
35 HAC Sensor signal.
41 Throttle Position Sensor signal.
42 Vehicle Speed Sensor signal.
43 Starter signal.
51 Switch signal.
52 Knock Sensor signal.
53 Knock Sensor signal.
54 Inter-cooler ECM signal.
71 EGR System.
72 Fuel Cut Solenoid signal.
78 Fuel Pump Control signal.
81 TCM Communication.
83 TCM Communication.
84 TCM Communication.
85 TCM Communication.



GOOD LUCK ALL

PEACE
VINNIE

 

awesome info! thanks vinnie!

 

:eek: ehehehe turbo Lexus huh (I know its the same as Toyota)

 

I just replaced my o2 sensor 2,3 weeks ago. I took some pictures so I can write up the page shows how to replace o2 sensor etc..
I got code 25 as well, but after the reinstallation, it feels much stable condition.

 

Just playing around I pulled out a front sensor. It has a standard connector. The rears (on my LS400) are a different matter. The wires go into the floor pan and that hole has a rubber grommet. I could not locate a connector to remove Anyone know how to accomplish this ???

 

the wire connects under your back seat...pull out the back seat and trace the wire out....im almost positive thats' where it connects.. and by the way can you tell me exactly where the front o2 sensor is located im sure it's in the same place on the sc

 

Guys/folks:

I had a new audio system installed.

I earlier had a diagnosis (Lexus and independent) of rear o2 sensor failire.

The Trac is not working (unsafe, with the power..dry; and undrivealbe wet or snowy)

They're telling me that the the O2's out cause the tandem Trac light to illuminate and prevents the Trc from engaging...(!!??)

I'm skepticai..any advice???

 

if your TRAC light is light along with your check engine light then it's 90% an 02 sensor. Which one, is the trick. Read my 1st post and you will see how many and where the sensors are. Also if you had lexus diagnose it ask them what ERROR CODE DID THEY GET (26 OR 25). Also ask them if the problem was with upstream air flow or downstream airflow upstream means it's the two front ones/the other are the back two..........

 

Thanks, buddy

 

So I was drive on the parkway at about 90-100 mph and my traction control light and check engine light came on...... i'm gonna get my O2 sensors checked but could this because i just got my injen short ram and flow master mufflers with my resonaters deleted........I've had the mods for a month now but today was the 1st time I opened the car up. I've also been using V-power gas from the Shell gas station.

 

This is the code I am getting. When I go to the auto parts store what do I ask for? I cannot find ANYTHING that shows a part number or location for a "sub" o2 sensor.

Here is a list of o2 sensors for a 95 SC:

http://www.rockauto.com/catalog/rafr...1356128k501777

The word "sub" is nowhere to be found. AND it seems there are 2 upstream and 2 downstream sensors, so would "sub o2" mean 2 sensors need to be replaced?

 

Wow, I'm in the wrong business.

There is actually a test to see which o2 sensor is failing, but I would go ahead and replace both anyway.

Any weekend shadetree mechanic can change both front o2 sensors themselves, with some basic tools.

If you are really on a budget, there are some universal o2 sensors that you can use, about half the price, you just have to splice them into your original connector.

I hope we can get more information out there to the public, so we can stop sending mechanics' kids to college for a simple o2 sensor replacement.

 

I believe once the check engine light goes on it will turn off the traction control system. Thus, both light will turn on. If you look closely, you see the check engine light go on and then the traction light. I know this because I also thought that i had O2 sensor problem, but the check engine light was due to EGR after already changing out the sensors...wished i would've pulled the code before coming to a conclusion that it was bad O2 sensors.

 

I have no problem changing "both" sensors, but from what I'm seeing there are 2 sets of them. Is this correct? I don't want to waste $$ on a set that is good.

 

thanks for the codes man, putting them in a word doc, and adding to my LEX binder.