Hi all, I have the most amazing car 2011 Acura TSX wagon. 120k, drives like a dream. However after I took it for an oil change (not at dealer) it suddenly feels different. While accelerating, it's revving much higher than before, at 4000 rpm, to get to 40, 50 mph. And it's even more sluggish to get higher speed. It almost feels car lost 30-40% power. Never experienced this in past 13 years I am driving it. Something definitely changed, but can't figure out. I challenged the shop, they say they didn't touch anything except changing oil and filter. I am not a total car nut but technical enough to troubleshoot and do simple car maintenance. If anyone here can guide me I will be very grateful.