Grooved the 5.3 no problem. Started the engine check engine light came on and loss of power mode. I tried to reset with the scanner no luck. I then pulled off the air snout and checked to make sure the groove looked alright and not too close to the butterfly looked fine. I then went to the relearn procedure no luck. I called Ron and asked for his advice and he said try cleaning the tps plug as hes had that do this same thing no luck. I decided to take back off and worse case refill the groove and while I had it off I noticed a small spur on the plain of the throttle body so I decided to sand this and the groove baby butt smooth. I then reinstalled the throttle body fireed it up and shazam perfect. Now for me to explain what I think happened, while I was cutting the groove I noticed the stem on my bit was bent slightly and this is what I think caused the tiny spur and I mean tiny.The butterfly didnt seem to be hitting anything but it must have, So if you run into this problem look close at the cut. I plugged the pcv at intake center and on throttle body turn down,runs like a top and customer very excited. The fuel trims before were pos 5s long term 4s short now with the groove long term neg 6 short neg 5 this means it already on its way to better mileage. Dan gadgetman Mo.