I just noticed an issue pop up since its been cold. If my ECT is under the 63 degree catylist warmup the truck will have a 3/4 shift flare under light throttle. If it goes into high idle catylist warmup it wont flare but it will surge until the temp is about 160ish. The truck is a stock 2017 silverado 5.3. Any idea what would cause this?