Originally Posted by TheMadScientist
Looks like tip in enrichment.
I'll second this. When you're opening the throttle after the gear change, I'm sure it's quick enough to trigger tip-in enrichment. Try either logging the tip-in enrichment throttle plate % (it's called something like this) value if it is available with NA and see if the tip-in corresponds to the fuel dump. To test this, try rolling on the throttle slowly after a shift, keeping the tip in % value as low as possible or 0 and see if the AFR still goes rich.