My green 93 SC400 with 142K miles has giving me troble code 25. The car idle fine, good acceleration...
Has anyone got this code before?
Code 25 mean lean air fuel ratio, I checked the voltage between terminal VF1, VF2 and E1 of the DLC1. It looks like the problem is the left main O2 sensor.

Where is the Left and Right main O2 sensor? Do I have to look under the car?

The SC400 also has Sub-oxygen sensor, this sub-oxygen sensor is under the car.

The car has a total of 4 oxygen sensor ?

Thanks in advance

 

No one ever has a engine light stay on?
Don't tell me all your SC400/300 never had any probem yet

Am I the only one got problems? :eek:

 

I'm sorry not yet... Thank God!!!

VQT did you ever get that engine cleaned on your other SC?

 

That how I got this code on my Green SC400. The last owner never wash the engine, the engine was very dirty. The day I got it home, I wash the engine just like I did with my white one but with more degreaser and water. The car ran fine after the wash, had it park for a day, the wife drove it on the third day, that's when it develop the rough idle problem with bad acceleration...then engine light came on when I test drove it.
Found out that water did get in spark plug no. 5, dried it out, idle came back normal and good acceleration, but code # 25 kept showing up. Code 25 mean lean condition with the air fuel mixture.
With all the trouble shooting I done so far, it lead to the main Oxygen sensor...I need to check if the connectors are faulty and test them before replacing the sensors. The SC400 have 4 oxygen sensors:eek:
I don't know if this washing the engine is related to the problem or it's time the O2 need replacement...

Just change the oil and filter, transmission fluid, radiator fan fluid yesterday all were dirty. Going to change the plugs, wires, radiator fluid, thermostat before really looking into this code 25. I am hoping that new plugs and wire will solve the problem.

 

Your last post says the car runs fine but Code 25 is still displayed. Have you tried to clear the error code/s stored in memory by removing the DOME fuse in the engine compartment fuse box for longer then 10 seconds?

 

Did we lost a buch of replied on this post

 

YEAP...:eek:

 

From the dates of 9th - 10th...

 

With all the things happening the last few days, my main office is in NY city, can't communicate with the main office at all, can't concerntrate to work either
My branch boss called (our branch office located in NJ) and ask if I'll volunteer to go to NY once our main office call (I work for the federal Government), guess I am going to work on rebuiling WTC once they find every body under that mess...I used to go to work in NY city via the subway where it stopped under building 1 less than 3 years ago, there are many people still stuck in that subway tunnel under the building. Many people around here (Philadelphia area) worked in WTC did not come home...

I haven't have time to check the O2 sensors yet but it looks like I may have to replace it.
$227.42 each from Carson Toyota:eek:
Do you know anyone else sell Lexus/Toyota parts?

 

Try Iron Toad... a WEB based parts distributor for Lexus parts. They are actually a "back-door" of a real Lexus Dealer in PA. Always get the best prices.

 

Great site
Thanks 928owner

VQT 93 Green/pearl white SC400

 

Replaced two main O2 sensors Saturday, will find out if it fix the code 25 this week.
Found another dealer sell main O2 for $114 each, paid about ~ $240 for the pair with tax. Maybe Carson Toyota parts guy gave me the wrong price:eek:

It was very dificult to replaced even with right tools.