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TDIwyse · #77 08-31-2012, 02:12 PM

I'm sorry to do this, but going back and looking at some other data shows something that complicates the EGR data I posted yesterday . . .

The attached is from Feb of this year (pre recall) on a very long road trip. It was recorded with the Android Torque app at 5 sec intervals.

The EGR behavior appears to vary with the DPF loading. The data for the drive started with a fairly fresh DPF condition. The data shows the car doing a DPF regen around the "1700" time points where the EGR is very low for ~10 mins. Note that the closer the car gets to DPF regen time the lower the EGR utilization. And after the regen the EGR rate increases to heavy utilization. I also included the "engine load" and "speed" parameters to show the similarity in operating conditions as those things can also impact EGR.

So with the previous data I posted I'm not sure of the DPF condition for the "pre recal" EGR example for that mornings drive to work. The "post recal" behavior is on a recently regenerated DPF which means it's similar to the behavior in this graph.

So basically I'm retracting the conclusion I made that the EGR behavior is significantly different.

Sorry for the confusion . . .