vijayn

Thats ok, we hope you sort out the problem and if you can itl be good if you could post what the problem was in the end.

ALISC400

I would say this is perhaps the sensor/voltage issue, you can try lexus dealership in UAE *(Dubai and Sharjah) with their diagnostic test.
Otherwise best bet would be tuner shops which deal with Lexus but this will still be diagnostic and expensive in the short run.

IF you want to keep the car, best bet would be change the sensors otherwise my advice, try scrap for full cat (can get individual cut if needed).

NaVeeD

i wanna keep the car offcourse i love it
i tried taking it to the dealership but they only check GCC cars and the one i have is imported from Cali so no luck taking it to the dealer.

tuner shops i will have to see which one can do it
my car has started drinking petrol so much i have stopped driving it
its just parked from past 3days!

ALISC400

I have US spec and they accept but they are quite choosy and annoying sometimes. Try your luck in Dubai for Lexus dealership (sheikh zayed) otherwise try Al Nahda Auto in Ras Al Khor (heard from a friend its good but not tried myself)
Otherwise best bet is industrial area (sharjah) but that honestly is trial and error.

Fuel consumption seems to be the main issue here? Try checking any fuel lines for any leaks or even the fuel pump for any issues and rerun diagnostic test.
I guess more information is needed to help a bit better here but hope you find the solution soon!

D35tr0y312

My experience with zirconia O2 analyzers are that they are heated to 800*Celsius and the mV signals are close to 0mv when exposed to ambient air and 64mv when close to 1% oxygen. I am not sure if this is true in the automotive zirconia O2 sensors.

burteboy

Your O2 sensor functioning good problem is your AF sensor. Replace B2 sensor 1, that will take core of your check engine light. forget about the gas .

NaVeeD

Thank you everyone who ever replied to this thread
long story short a week back i toke it to the wiring shop all the wirings are fine he told me to change the sensor again i did change the sensor and removed all the codes i drove it for 4 to 5 days and again i got the check engine light and vsc again im thinking it would be the sensors again. Its a headache now taking it to the workshops again and again!!

burteboy

Could you please get the code itself .It will start with P. If you can get all the codes ,i will check all possible repairs for that concern and try to help you. think of when the code came and how long after u start to drive it would pop up.

NaVeeD

I will post it here as soon as i get the codes because i cleared it yesterday
Thank you once again

burteboy

That code is your main concern . It means your catalytic converter is below threshold . this means its not using up the oxygen as it should to lower the emission. you will have to replace your B2 catalytic converter. replacing that should correct everything else. i check your car diagram it shows you only have 02 sensors no A/F. TRUST ME ON THIS GUY. PS DOES YOUR VEHICLE HVAE ANY EXHAUST LEAK. LET ME KNOW.

NaVeeD

i dont have PO430 anymore because i have already changed the B2 cats and noni dont have any leaks i have checked that as well i am still waiting for the codes to show up as the car was just parked and i was out of country for some work.

vijayn

Hmm this is a strange problem. So you have changed all four o2 sensors twice and you have changed the cats? And the garage says the wiring is all good and the problem still exist.

Has anyone checked the heater signals on all four sensors? It would pay to check the 12V lines again to double check and also check the heater grounding signals that go to the ECU. Basically, the ECU has transistors that ground the heater coils that are inside the O2 sensors. I'm also wondering if the ground connection that the ECU uses to ground the heater coils is damaged.
Are you also able to show us realtime data of the all four O2 sensor readings from the scantool? (Make sure engine is warmed up)

Istehsan

This is one of the major issues in GCC countries unlike US or other places. Lexus dealer is too expensive and the some lexus workshops they are good in hammer works only. I tried 6 different special lexus workshops in Jeddah Saudi Arabia and no one seems to understand the problem. I am having sort of same issue that the fuel consumption is very high and only code I get is P0125.

NaVeeD

Keop

Hello everyone. Can someone help me with my 2000 GS300, I can't find/locate the coolant temperature sensor. Does anyone know the location and have pictures to help?