It's official, I'm an idiot.
 

What I needed to do was update the Foxwell. Once I did that it worked like a charm. The car started right up and seems to be running fine - I'm not sure what my earlier stalling problem was, but I just went for a test drive and had no hesitation. Cleared the D1 code and nothing came back.

The new software has a slightly different procedure for syncing the EWS than before: 1) Under "Main Groups" choose "Special Functions" 2) then choose "Immo & Keys" then 3) "Adjustment. engine control - EWS" and from there follow the instructions. It now tells you to turn the key all the way off and wait for 25 seconds - and gives you a countdown until you are good to go.

If you own a Foxwell NT510 Elite and haven't updated it, here is how:

First, ignore the online instructions that tell you the NT510 should be updated by registering at the old Foxwell website Foxwelltech.com. That is wrong and sent me on a wild goose chase. You MUST update the Elite by first registering at Foxwelltech.us.

Next you need to download Foxwell's updating App "FoxAssist", NOT "FoxScanner" which is the old App. You're supposed to be able to download FoxAssist from your "Registered Products" page, but that link was broken for me. I ultimately found it at: https://www.foxwelltech.us/support-tools.html

FoxAssist works on Windows 7, 8 and 10 only. Install, open it and log in with your Foxwell credentials.

Remove the micro SD card from your scanner (I thought it could be updated in the scanner via USB cable but apparently not). Use a card reader to connect it to your computer.

Your scanner should now show up on the "Download" tab of FoxAssist. Click "Update" and wait. When it says it's done you can put the card back in your Scanner and it will start up with the new software (the software lives on the microUSB card, your scanner is nothing without it.).

Slow speed stalling, eg: pull into intersection when light turns green butt pause to turn left and it stalls; almost always cam position sensor

Wow, awesome! Sure wish I would have known how to update my foxwell when I had my EWS get un-synchronized a couple years ago! I beat my head against it for a couple of weeks before I had it towed to a local indy and had them do it.

I beat my head against the wall too! But I'm happy now. There's nothing like an E53 when it's running right.

Thanks. My stalling was after I changed the fuel filter, the revs would drop and the engine would stall out at an idle (I never got to drive it more than 30'). Right now it seems to be running fine. Fingers crossed.

Thanks for all the help!