I think I messed up

[Ernie D]

I started my car this morning, it rough idled for a little bit, and the check engine light flashed on for a brief second.
I grabbed my peake code reader and connected it without thinking on shutting car back off and started to check for fault codes.
The code reader never showed a code on the display and the check engine light was steady on now.
I realized what I did having it running, and I shut the car off and tried again, I plugged the peake tool back in and tried scanning for codes again, and it just shows its searching, I let it search for 10mins or so, no luck, tried resetting codes with no luck.
So I performed a stomp test, code 1213 showed up, which was some kind of rich/lean situation.
I started the car back up and the code disappeared and the car started running fine.
May I have screwed up my peake tool? Or did I screw up my diagnostic circuit on the dme?
It performed the stomp test without any hangups

[Mykk]

After working in the automotive repair industry for over a decade, owning and using various scanners. I don't think anything anywhere got screwed up. It just sounds like you had a computer/sensor input/feedback hickup that cleared up once the correct voltage from the car was supplied after running it and shutting it off.

If the car started up and runs fine now I wouldn't think much else of it, if it continues to happen then you should start diagnosing.