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Engine Warning Light Has Come On


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Driving home from work tonight and the engine malfunction light came on.Engine sounds ok and running the same so i am a bit concerned as to what it is , hopefully some of you guys might have some ideas as to what it might be.

The car is a 2003 gs 430 sport any help is much appreciated .

Cheers James

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The light could mean anything. Oxygen sensor etc.

I had driven it last week when it was very very low on fuel (needle on the bottom of the dail) read on a couple of threads about this being done and then the light comming on , could this maybe had an effect ?

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It's conceivable that it had an effect, perhaps (for example) the very low fuel meant that the gunge in the bottom of the tank concentrated around the pump and filter which could have meant it was having trouble pulling fuel through. I wouldn't have thought that to be especially likely, though...

The ECU should have recorded what caused the light to come on. Is it still doing it, or has it gone off again now?

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It's conceivable that it had an effect, perhaps (for example) the very low fuel meant that the gunge in the bottom of the tank concentrated around the pump and filter which could have meant it was having trouble pulling fuel through. I wouldn't have thought that to be especially likely, though...

The ECU should have recorded what caused the light to come on. Is it still doing it, or has it gone off again now?

Its still doing it m8 perfomance is still good though and fuel comspution is ok aswell .

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Hi, You will have to take it down to Lexus or a reputable Indie that has the correct Diagnostic equipment to Read your Fault codes stored in the ECU..........It could be a Mutitude of things but is more than likely to be a Sensor!

..The fact your car is still performing OK means there is no cause for alarm!...But get the problem fixed ASP! If you leave it ,it could cause More Damage!!!!!

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Hi guys had a m8 of mine use his diagnostic kit on my car at the weekend and he found the fault .The fault code was po155 and it said it was the 02 sensor heater circuit bank 2 sensor 1.

Was just wondering whereabouts should we look and where is it placed and is it a diffilcult job to do ?

And as ive said before on previous posts thanks your help.

James

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Hi guys had a m8 of mine use his diagnostic kit on my car at the weekend and he found the fault .The fault code was po155 and it said it was the 02 sensor heater circuit bank 2 sensor 1.

Was just wondering whereabouts should we look and where is it placed and is it a diffilcult job to do ?

And as ive said before on previous posts thanks your help.

James

Did he cancel the warning for you and see if it comes back??????It could just be a transient.I have just bought the mongoose interface and am using the techstream software .It is amazing what you can see with this kit.

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The code indicates the pre cat O2 sensor is faulty due to it's internal heater element failing or the supply to it or the wiring, normally this is located on the exhaust pipe before the catalytic convertor, may be incorect but there are normally 2 pre and 2 post cat sensors ( so 2 for each bank of cylinders).

Before jumping in with a replacement check the wiring to it is sound and the same at the other (ECU) end.

With a fault like this present the engine ECU normally adopts preset backup fueling levels but if the mixture is too rich damage could occur to the cats over a period of time.

Typical 4 wire O2 sensor

o24wire.gif

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The code indicates the pre cat O2 sensor is faulty due to it's internal heater element failing or the supply to it or the wiring, normally this is located on the exhaust pipe before the catalytic convertor, may be incorect but there are normally 2 pre and 2 post cat sensors ( so 2 for each bank of cylinders).

Before jumping in with a replacement check the wiring to it is sound and the same at the other (ECU) end.

With a fault like this present the engine ECU normally adopts preset backup fueling levels but if the mixture is too rich damage could occur to the cats over a period of time.

Typical 4 wire O2 sensor

o24wire.gif

Cheers for that very imformative did not know it was situated on the exhaust should make finding and dealing with it a bit more easier thanku steve. Nicnac yes he did cancel it but it came back on within a couple of hours , i am concern about causing more damage and am going to try and get it fixed ASAP as it desperately needs a service aswell .

Thanks to both of u for replying very helpful the both of you have been.

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