Where is the Main oxygen sensor signal on right bank?
08-11-13, 09:53 AM
#2
There are 4 02 sensors. The ones on the exhaust manifold (pre cat / upstream) are the main sensors. Bank 1 is drivers side, bank 2 passenger. The other two are after the catalytic converter. These are for emissions.
Very simple, you should not need a diagram. If you do, Google is your friend.
Very simple, you should not need a diagram. If you do, Google is your friend.
08-11-13, 10:37 AM
#3
Lexus Champion
the two O2 sensors (one on each exhaust) on the engine side of the catalytic converter are the important ones that affect how the car runs
the two on the rear end of the catalytic converters are only there to tattletale to the emissions authorities that you have been a bad boy!
the two on the rear end of the catalytic converters are only there to tattletale to the emissions authorities that you have been a bad boy!
Last edited by LScowboyLS; 08-11-13 at 10:44 AM.
08-11-13, 02:19 PM
#4
the two O2 sensors (one on each exhaust) on the engine side of the catalytic converter are the important ones that affect how the car runs
the two on the rear end of the catalytic converters are only there to tattletale to the emissions authorities that you have been a bad boy!
the two on the rear end of the catalytic converters are only there to tattletale to the emissions authorities that you have been a bad boy!
08-19-13, 09:02 PM
#5
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AFR sensor and oxygen sensors
Please make sure that if your car has AFR sensor (air fuel ratio) then you replace it with an AFR and if you have oxygen sensor then r,eplace it with oxygen sensor since signal detection circuitry inside the ECM looks for a specific voltage range for feedback signal. If the feedback signals are different then ECM will throw cel light and could also lead to damaging the ECM. Thanks
08-19-13, 09:29 PM
#6
Lexus Champion
throw a code?, yes
damage the ECM (ECU)? - not a snowball's chance in hell, unless you totally put something on your Lexus that is not intended for the model and year you have, and this would require changing the harness connector, etc.
LS400's use normal heated Zirconia element O2 sensors, not the newer AFR sensors, and for that matter, folks should stick with genuine Denso, the same company who designed and built your original O2 sensors as well as your ECU (ECM)
how the O2 sensors operate:
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three–way catalytic converter is used, but for the most efficient use of the three–way catalytic converter, the air–fuel ratio must be precisely controlled so that it is always close to the stoichiometric air–fuel ratio.
The oxygen sensor has the characteristic where by its output voltage changes suddenly in the vicinity of the stoichiometric air–fuel ratio. This characteristic is used to detect the oxygen concentration in the exhaust gas and provide feedback to the computer for control of the air–fuel ratio.
When the air–fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen sensor informs the ECM of the LEAN condition (small voltage: 0 V).
When the air–fuel ratio is RICHER than the stoichiometric air–fuel ratio the oxygen concentration in the exhaust gas in reduced and the oxygen sensor informs the ECM of the RICH condition (large Voltage: i.e. 1V).
The ECM judges by the voltage from the oxygen sensor whether the air–fuel ratio is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor causes output of abnormal voltage, the ECM is unable to perform accurate air–fuel ratio control.
The heated oxygen sensors include a heater which heats the Zirconia element. The heater is controlled by the ECM.
When the intake air volume is low (the temp. of the exhaust gas is low) current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
Last edited by LScowboyLS; 08-19-13 at 09:56 PM.
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08-20-13, 10:36 AM
#8
the two O2 sensors (one on each exhaust) on the engine side of the catalytic converter are the important ones that affect how the car runs
the two on the rear end of the catalytic converters are only there to tattletale to the emissions authorities that you have been a bad boy!
the two on the rear end of the catalytic converters are only there to tattletale to the emissions authorities that you have been a bad boy!
08-26-13, 05:52 AM
#9
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Ok
I'd read the ECM part somewhere on other forums but CEL ON issue was being faced by me on my 2003 GS300. I'd bought 2 sensors, front and back for 1 cylinder bank however, one was O2 and the other AFR which i didn't know and CEL never shut off. Hence, after self studying and going through the forums i figured out why. Then i changed AFR to O2 which fixed things. Just for caution i mentioned it here, trusting my source as O2 sensor is cheaper than the ECM.
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zajacjoe
SC430 - 2nd Gen (2001-2010)
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