Modern Vespa

I have a 2022 Vespa Gts Super. Been fantastic until recently. My engine light keeps coming on but runs great. It usually happens when outside temps are above 85 degrees. I checked gas cap and released pressure then light would go off. I got tired of this so I removed my evap system and had no problems since until today. I rode round trip to pick up some supplies and I was coming home my light came back on. Normally I would only use about 1/2 tank of gas but today it really used much more than usuall. My speed varied between 45 and 65mph. When the bike cooled down after I got home and recycled ignition couple of times and now light turned off. My question is could this be the beginning of my o2 sensor going out?

Doubt it.

Evap was my first guess but you've removed that.

Scanning the codes would be handy (any cheap scanner).

Important question: what parts of the evap did you remove and alter? You must replace the one-way check valve that is close to gas cap. Evap models use a red valve, non-Evap models use green check valve. You must switch or the tank will not vent when level goes down and this will cause fuel starvation problems. Red valves open with cylinder vacuum, green ones are low pressure.