Failed Inspection.....???
I live in Fl so we don't worry about inspections and I'm no expert in this but just trying to take a pick at this.
Could be like you said the 02 sim is prob acting up or the scan program they are using just doesn't like the 02 sim
I live in Fl so we don't worry about inspections and I'm no expert in this but just trying to take a pick at this.
Could be like you said the 02 sim is prob acting up or the scan program they are using just doesn't like the 02 sim
I think Ming is onto something with the Randomtech cat failures. The ECM may be running this rich test and since it sees no response from the secondary O2, it runs rich waiting for a response longer than it should and overheats the cats. Apparently, the simulator is good enough to keep from setting a DTC, but not good enough to prevent catalyst failure.
From the Factory Service Manual:
The first sensor, the air fuel ratio sensor, sends pre-catalyst information to the ECM. The second sensor, the heated oxygen sensor, sends post-catalyst information to the ECM.
In order to detect any deterioration in the three way catalytic converter, the ECM calculates the oxygen storage capacity of the three way catalytic converter. This calculation is based on the voltage output of the heated oxygen sensor while performing active air fuel ratio control, rather than the conventional detecting method, which uses the locus ratio.
The oxygen storage capacity value is an indication of the oxygen storage capacity of the three way catalytic converter. When the vehicle is being driven with a warm engine, active air fuel ratio control is performed for approximately 15 to 20 seconds. When it is performed, the ECM deliberately sets the air fuel ratio to lean or rich levels. If a rich-lean cycle of the heated oxygen sensor is long, the oxygen storage capacity becomes greater. There is a direct correlation between the oxygen storage capacities of the heated oxygen sensor and the three way catalytic converter.
I think Ming is onto something with the Randomtech cat failures. The ECM may be running this rich test and since it sees no response from the secondary O2, it runs rich waiting for a response longer than it should and overheats the cats. Apparently, the simulator is good enough to keep from setting a DTC, but not good enough to prevent catalyst failure.
From the Factory Service Manual:
Also. this isn't something you'll see on a dyno test or tune without running at steady state for a considerable time, so "tuning" around this is going to be very challenging and likely expensive.
Last edited by caymandive; Sep 6, 2011 at 07:48 AM.
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If he had an error code he would have failed for that, a system not ready is completely different.


