2014 ZL1 with intake and exhaust tuned by a local shop. Owner wasn't happy and wanted me to take a look at it. This is my first ZL1/6L90e and I just can't figure out where to go with it. So I joined up here looking for some input, knowledge, and hopefully a place to learn. The issue is the car 20% of the time will not hit its shift at WOT in Drive or Sport. TUTD 2-3 goes right to redline, and 3-4 4-5 will either flare badly or also go straight to redline.
Fran

