Can anyone diagnose why I went into limp mode here?

[George Rosebush]

I also got a tire puncture on the same lap, not sure if the two are related. I have a 2015 auto and the code thrown was U0073. Here's the lap:

The limp happens at about 1:47. The tire was punctured by a rather large piece of metal, you can hear it in the later half.

By the way, this happened at Chuckwalla, my very first trackday ruined by this rather early, I had one session before this, and this was the first lap of the second session. Everyone was very helpful, they tried to find a tire for me but couldn't, so I ended up having to drive on the spare donut crawling on the highway for an hour and get a new tire. They also are giving me a free trackday, so not all is lost and I do want to go back, this time with a new set of wheels and tires and a full size spare or two.

[strat61caster]

Were you running any data logging and did the car eventually take itself out of limp mode when you reset/cleared codes or is the code persistent?

[George Rosebush]

I was running torque app, it found the same code other scanners did, the U0073, and it is not persistent, we cleared it and everything seems fine.

[cjd]

OBD will trip limp mode sometimes if there's a bad connection to a device plugged into the circuit that's cycling on/off or connecting/disconnecting repeatedly. I ran into this with the 86Nanny I used to have; the connectors were faulty in that case (easy fix once it was sorted out.)

[strat61caster]

Originally Posted by George Rosebush

I was running torque app, it found the same code other scanners did, the U0073, and it is not persistent, we cleared it and everything seems fine.

I would recommend not leaving the scanner plugged in all the time, the OBD2 can be a primadonna about that sort of thing. Start the car then plug it in when necessary otherwise leave it out, this is a common issue. I believe it will act normally for a few power cycles but it'll probably pitch a fit at least once per track day if you leave it in all day.

https://www.ft86club.com/forums/showthread.php?t=61958

Everything else seems fine, hope your next track day goes better!

[George Rosebush]

That makes a lot of sense, thanks.
To anyone wondering, apparently from that thread linked, the problem is running the Torque app while the car is starting, not the adapter itself.