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Lav, I came across this "Techstream ECU Flash Reprogramming Procedure". Not sure if this is helpful to update ECU software.
Thank you RKW. It is interesting to read about it. You need to be connected to to the Lexus sever to download and update from what I understand. I don't need to update anything but if I did I would not want to risk screwing up the ECU. Even the well know Lexus independent shop in Atlanta does not perform these as they have had problems with ECU's failing during the process.
Just ordered BOTH of them, via Amazon. No idea how long I'm going to keep the LS, and I'd rather just have the driver's side O2 sensor 'on-hand'. Who knows, I might get lucky and have an ez time doing the passenger side and go for the gusto and do the other side. I've heard a faulty O2 sensor can noticeably affect gas mileage/fuel economy? I haven't noticed any decrease in my MPG, although this just happened last week.
I also ordered an offset socket thingy for $8. Hope I can make use of it. If not, just another tool in the drawer.
Provide the different part numbers for each different part ...
P0031 is oxygen sensor on LS - bank one sensor one. It is mounted in the manifold before the Catalytic converter. You may call it an air/fuel ratio sensor.
Air / fuel sensor seems more like a generic term. As Tom mentioned, O2 sensors combined with the the engine temp sensor regulate fuel to air ratio. Post cat or downstream O2 sensors are only there for emissions. To make sure you don't remove the cats.
Engine management systems
The stoichiometric mixture for a gasoline engine is the ideal ratio of air to fuel that burns all fuel with no excess air. For gasoline fuel, the stoichiometric air–fuel mixture is about 15:1 i.e. for every one gram of fuel, 15 grams of air are required.
Any mixture greater than ~15 to 1 is considered a lean mixture; any less than ~15 to 1 is a Rich mixture – given perfect (ideal) "test" fuel (gasoline consisting of solely n-heptane and iso-octane). In reality, most fuels consist of a combination of heptane, octane, a handful of other alkanes, plus additives including detergents, and possibly oxygenators such as MTBE (methyl tert-butyl ether) or ethanol/methanol. These compounds all alter the stoichiometric ratio, with most of the additives pushing the ratio downward (oxygenators bring extra oxygen to the combustion event in liquid form that is released at time of combustions; for MTBE-laden fuel, a stoichiometric ratio can be as low as 14.1:1). Vehicles that use an oxygen sensor or other feedback loop to control fuel to air ratio (lambda control), compensate automatically for this change in the fuel's stoichiometric rate by measuring the exhaust gas composition and controlling fuel volume. Vehicles without such controls (such as most motorcycles until recently, and cars predating the mid-1980s) may have difficulties running certain fuel blends (especially winter fuels used in some areas) and may require different jets (or otherwise have the fueling ratios altered) to compensate. Vehicles that use oxygen sensors can monitor the air–fuel ratio with an air–fuel ratio meter.
Provide the different part numbers for each different part ...
P0031 is oxygen sensor on LS - bank one sensor one. It is mounted in the manifold before the Catalytic converter. You may call it an air/fuel ratio sensor.
I know what o2 and af sensors are. You may call it a o2 sensor but pre cat its called af sensor. Check your hood tag emissions label. Should say af somewhere.
Terminology is technically different, but everyone knows the words are synonymous and used interchangeably. The point is, the OP needs a new bank one sensor one. You are making it sound as if the OP needs a sensor other than the one to which he was directed.
In the LS430 repair manual, the terms AFS (Air-Fuel ratio Sensor) and Oxygen Sensor are used interchangeably. It appears that Sensor #1 (located up-stream of the CAT) and Sensor #2 (located down-stream of the CAT) are measuring and capable to produce the same "type" of output waveform. In fact, the ECM compares the 2 waveforms to determine if the CAT is doing its job (as shown below).
Terminology is technically different, but everyone knows the words are synonymous and used interchangeably. The point is, the OP needs a new bank one sensor one. You are making it sound as if the OP needs a sensor other than the one to which he was directed.
Yes everyone continues to call them o2 so consumers dont get confused.
08-10-15, 10:22 AM
