Hello, a couple of weeks ago, my Stabiltrak and Traction control lights came on while I was driving. The check engine light starts flashing (misfire), and not always, but I will lose power, also, when this happens, it will shift very hard from 1-2 and noticeable from 2-3. Will the lifter noise (which doesn't go away) cause the misfire? My code reader is showing P0121 (Throttle Position Sensor) and P0301 (cylinder 1 misfire). Can the TPS be the culprit for these problems? By the way, I have a 2007 GMC Sierra (new body) with 5.3L and active fuel management. Also, can the lifters be removed from the top through the push rod holes?
