2006 F350 CC - I logged my drive home a couple of days ago and saw something weird on the graph.

Spreadsheet from the same drive:
L-r columns are time (sec), speed (km/h), IPR%, RPM, boost, VGT%, command gear

Today I was able to replicate the drops in boost on the same drive. It's a hill heading out of town, and half way up the speed limit changes from 70 km/h to 100. The first time I could see a couple of slow vehicles ahead that I wanted to pass before the road narrows to one lane in each direction. Today I stepped on it just to see if the same thing would happen. It did.
I didn't notice anything performance-wise that would have led me to suspect an issue either time.

Today's drive

 

I guess I didn't get to my questions - does this look ominous? Are there other PIDs I should monitor to get a more complete picture? Would you start by giving sensors, turbo etc a good cleaning?

 

I don't think I'd sweat it. If it's driving fine I would guess it's some sort of data collection or reporting error. I say that because you are losing all boost yet the VGT value should actually be moving very little because it appears your boost level is pretty consistent thru the snapshot.
If I was concerned, I'd plumb a gauge into the intake side and grab an independent set of data.

 

Using WiFi or Bluetooth? Probably can’t transfer data fast enough for accurate live streaming.

 

It's Bluetoooth. I hadn't considered data lag, maybe I'll try it in my Excursion (which I just got back today!) and compare.

 

...and here's a chart from the Ex, same hill. I'll chalk it up to data speed and not worry about it. Thanks
Laurel-Anne

 

How sure are you it's got a stock PCM tune in it? Guy named Shane had this issue with a DashBoss, not sure if he ever found a resolution. Hasn't been back in a year+.

It used to be an issue on ScanGauges with an old coding for how the MAP subtracted BARO to derive Boost. If there's no leak in the MAP hose and that sensor is in range, I'd just accept that it's a software quirk and not worry. Or put in a mechanical boost gauge.

 

I'm pretty sure the crew cab is stock. The guy we bought it from got it new from the dealership and didn't mention a tuner. He's a rancher and doesn't strike me as the type to bother with tuning, but I guess there's a possibility.
We've been focused on getting the Excursion back in the road and haven't given the CC a good check up yet, so it's always possible there's a leak.

The Excursion came with a SuperChips programmer but we returned it to stock shortly after we bought it. I don't know enough about programmers to know if we can trust that it's actually back to stock. I was hoping to find out this week from my mechanic, but he said his scanner (Snap On, I think) can't read that.

In another thread here, about custom tunes to turn off CEL after an EGR delete I mentioned that I was waiting to see if my CEL would come on - it did. I'll reply on that thread, too, but I think that means it's not an original stock PCM strategy for a 2004 engine, right? September 2004 build date.

This is getting long, but perhaps this is related. We have lent both of these trucks to a friend to haul horses with, and she claims the crew cab is "way better" for towing. More power, and holds back better on downgrades. Could a difference in PCM strategy account for that, assuming my friend is correct? Although, this was before all the engine work on the Excursion, so that could play into it too, I guess.

 

Just to follow up on this, I checked with Dashboss support and he agrees that it's basically noise. Dropout could be ECU or Bluetooth, baro or MAP.