For some reason, my engine has been stalling randomly after startup. It's only on startup, never happens more than once during a trip (after starting up the second time, everything is always fine and never stalls while driving), and is totally random - sometimes cold start, sometimes hot start.

It's sporadic enough that I've just been dealing with it. But twice now, the engine has stalled when starting up from the start/stop system – while I was in the middle of an intersection. Left me a sitting duck until I completely restarted the car by pressing and holding down the start button. Not ok.

My initial thought is wonky mass airflow sensors, but have not found any trouble codes or faults with my Gap IIDtool. Even pulled them out to inspect and they were pristine clean.

Any ideas? 2021 P525 | Eiger Gray

I'd have a look at the throttle body, in my experience anything supercharged ends up pulling garbage back through the intake via some breather and it settles around the blade of the TB. On cold start that garbage inhibits airflow and you'll stall or have loopy idle. I'm not sure where the TB is on the l405 but on the l322 it was on the back side of the engine which made access sort of annoying. Regardless find it (hopefully up font) pin the blade back and have a look. If there is trash all around the plenum behind the blade clean it.

You can clean it up while on the car but I prefer removing it and giving it a solid cleaning with a wire wheel and some carb cleaner so on startup nothing is getting sucked into the intake.

Once it stalls does the display screen go in 4x4 mode ??? 2015 4.4 AB
GSXR 1000 K5
R1 1998

No, screen just goes dark like I’ve shut the car off. 2021 P525 | Eiger Gray

Disconnect your negative cable to the auto stop start mini battery or solenoid in the trunk and you won’t have to worry about it.