Pulled my 18 850 Backcountry out for the first ride this season, first couple laps around the yard was running fine then developed a miss when I would try to go more than 50% throttle then started doing it at less RPM. It’s intermittent as it comes in and out of it, sounds like it’s dropping down on 1 cylinder. No check engine light. After the sled is warm when starting it will backfire and shut off. Are these classic Symptoms of a TPS sensor failure or out of adjustment?