07 Mustang GT,automatic. Just installed the Flowmaster Axle-back kit and it sounds sweet, but 2 days later I began to notice a loss in power, but I'm sure if its related to the exhaust change. Whats happening is while I'm accelerating and I reach 40 mph the transmission shifts and I get a load groan and the RPM goes to about 1700. I continue to press down the throttle and I get almost no response or just a little response. The only way to get out of that is either back off the throttle and re-apply or just slowly bring it to wide open throttle which would force a shift to get back the power band. It always has done this on occasion but now its worse after the exhaust install. 1 other note, I have heard people say that exhaust clamps alone without welding is a bad idea. And that a leak can develop at the slip-fi connections, could that be why for loss of acceleration/power? And can a leak there actually rob power?