Well, my 2015 F3-S SM6 is unridable AGAIN... with only 3500 miles on the odo, it once again runs like poo. Details:

Starts right up, runs perfectly for a few seconds, then settles into a sputter/almost stalling at idle, with backfiring if the throttle is twisted. Jerks pretty hard if attempted to ride (so of course I don't ride it) Previously, it had gone to the dealer multiple times for a similar issue, but threw error codes (02 sensor and shift angle sensor, of which they replaced the 02 sensor on the second visit). But this time, it is not throwing error codes. Hesitant to send it back to the dealer, because it's out of warranty and I'm out of money ha ha. Meanwhile, I bought a new battery, put fresh gas in it (in case there was an issue with the previous batch of gas). No difference.

Then it started having the headlights come on randomly, even with the key nowhere near the ignition. So it didn't take long to drain the new battery. Seriously, gremlins?

I guess I might have no choice but to send it to the dealer again... but is there anything I should check beforehand? I'm not familiar with all the electronic equipment in this machine, but I am pretty handly with general mechanical stuff, so willing to try something if you folks have any brilliant thoughts