need help on reading live data
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Driver School Candidate
Joined: Jun 2016
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From: GA
need help on reading live data
If anyone can point out whether these numbers are typical (or something abnormal) would be greatly appreciated.
taken while on idle (2005 ES330)
sparkadv - ranges from 4 to 30 but seems to average out around 15.
MAF (g/s) - averages out around 3.
TP(%) - 15
O2B1S2 - around 0.78 V (constant, does not change unless the gas is pushed then it goes to 0 V, then climbs back up)
O2B2S2 - around 0.76 V (same as the above, does not seem to change unless gas pedal is pushed then it goes to near 0 V)
SHRTFTB2S2 - 99.2%
EQ_RATB1S1 - 0.992
O2B1S1 - 3.2 V (constant, no change)
EQ_RATB2S1 - 1.007
O2B2S1 - 3.3 V (constant, no change)
no codes
taken while on idle (2005 ES330)
sparkadv - ranges from 4 to 30 but seems to average out around 15.
MAF (g/s) - averages out around 3.
TP(%) - 15
O2B1S2 - around 0.78 V (constant, does not change unless the gas is pushed then it goes to 0 V, then climbs back up)
O2B2S2 - around 0.76 V (same as the above, does not seem to change unless gas pedal is pushed then it goes to near 0 V)
SHRTFTB2S2 - 99.2%
EQ_RATB1S1 - 0.992
O2B1S1 - 3.2 V (constant, no change)
EQ_RATB2S1 - 1.007
O2B2S1 - 3.3 V (constant, no change)
no codes
Thread Starter
Driver School Candidate
Joined: Jun 2016
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From: GA
Also, wondering what the sparkadv numbers are supposed to be.
Pole Position
Joined: Feb 2017
Posts: 368
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From: CA
The car sometimes hesitates and jerks on the highway and has delay issues in the acceleration from time to time. I'm wondering whether the oxygen sensors are working properly or if there is inadequate amount of air flow into the system. Shouldn't one of the sensors be changing from 0.1 V to 0.9 V? Whereas my readings seem to be constant at idle. The fuel trim data is reading well but the car changes from CL to OL drive from time to time, which may mean that it's disregarding input from the oxygen sensors occasionally.
Also, wondering what the sparkadv numbers are supposed to be.
Also, wondering what the sparkadv numbers are supposed to be.
The downstream O2 sensors are not wideband, so they basically go from 0V to 1V, which is lean to rich. When you press on the gas, it dips because the throttle opens and more air is passing through before the ECU reads that (via the MAF) and compensates with more fuel to bring it closer to stoich.
When does it go open-loop? At WOT, cars go open loop (the ECU relies on a lookup table entry). Some vehicles (BMW's larger engines) go open-loop on throttle closure at speed (under normal engine braking).
Are you sure it isn't the quirky behavior of the drive-by-wire Toyotas? I refuse to own a DBW Toyota myself, but maybe somebody else can help you figure that out
Thread Starter
Driver School Candidate
Joined: Jun 2016
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From: GA
Well, spark advance will change with engine RPM; specifically, it'll go up as the ECU wants to ignite the air-fuel mixture earlier so the flame front coincides with the piston getting to TDC faster at higher RPMs.
The downstream O2 sensors are not wideband, so they basically go from 0V to 1V, which is lean to rich. When you press on the gas, it dips because the throttle opens and more air is passing through before the ECU reads that (via the MAF) and compensates with more fuel to bring it closer to stoich.
When does it go open-loop? At WOT, cars go open loop (the ECU relies on a lookup table entry). Some vehicles (BMW's larger engines) go open-loop on throttle closure at speed (under normal engine braking).
Are you sure it isn't the quirky behavior of the drive-by-wire Toyotas? I refuse to own a DBW Toyota myself, but maybe somebody else can help you figure that out
The downstream O2 sensors are not wideband, so they basically go from 0V to 1V, which is lean to rich. When you press on the gas, it dips because the throttle opens and more air is passing through before the ECU reads that (via the MAF) and compensates with more fuel to bring it closer to stoich.
When does it go open-loop? At WOT, cars go open loop (the ECU relies on a lookup table entry). Some vehicles (BMW's larger engines) go open-loop on throttle closure at speed (under normal engine braking).
Are you sure it isn't the quirky behavior of the drive-by-wire Toyotas? I refuse to own a DBW Toyota myself, but maybe somebody else can help you figure that out
Pole Position
Joined: Feb 2017
Posts: 368
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From: CA
On older cars with slower-responding/primitive closed-loop operation, yeah. But these have wideband sensors upstream and better algorithms. The ECU uses the upstream (wideband) sensors to decide how much fuel to inject at a given throttle (let's assume the amount of air at a given throttle position is unchanging, as verified by a properly-functioning MAF). So the exhaust coming out, assuming everything else is the same, is going to be the same mixture (i.e., have the same amount of oxygen) and the downstream (narrowband) sensors will read that until the throttle changes. The downstream sensors aren't used to make decisions per se, they're just to monitor cat operation.
Thread Starter
Driver School Candidate
Joined: Jun 2016
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From: GA
On older cars with slower-responding/primitive closed-loop operation, yeah. But these have wideband sensors upstream and better algorithms. The ECU uses the upstream (wideband) sensors to decide how much fuel to inject at a given throttle (let's assume the amount of air at a given throttle position is unchanging, as verified by a properly-functioning MAF). So the exhaust coming out, assuming everything else is the same, is going to be the same mixture (i.e., have the same amount of oxygen) and the downstream (narrowband) sensors will read that until the throttle changes. The downstream sensors aren't used to make decisions per se, they're just to monitor cat operation.
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Pole Position
Joined: Feb 2017
Posts: 368
Likes: 39
From: CA
That, or there's a fault code set for the ABS system. You should read the code(s) and report back.
If a cat is going bad, it will almost always throw a P0420. Bad gas - as rare as it is nowadays - is unlikely to kill a cat. They just reduce in efficiency over time, might be due to diminished catalytic action, or due to being dirty.
If a cat is physically clogged, you can test it by seeing how the car performs at WOT normally, and again after removing an upstream O2 sensor (which will allow exhaust past a restriction). If the car wakes up with the O2 sensor removed, you have a clogged cat.
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Pole Position
Joined: Feb 2017
Posts: 368
Likes: 39
From: CA
That reminds me, there's a guy that reviewed a Chinese throttle controller recently that you might be interested in OP. Far cheaper than the name-brand ones and seems to do the same thing. That seems to be the main solution for the DBW "problems."
EDIT: Here: https://www.clublexus.com/forums/es-...l-lag-fix.html
EDIT: Here: https://www.clublexus.com/forums/es-...l-lag-fix.html
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