2002 Tahoe Z71 5.3 176k miles So I've been trying to figure out why my Tahoe is stumbling/surging between 40-60. I replaced all the usual suspects, fuel filter, pump, spark plugs, wires, cleaned the throttle body, cleaned the cone filter (k&n previous owner installed it...). I've had a CEL so I bought a scan tool. It said knock sensors, I cleared it, cel came back after a day and it said the same thing. So I looked into symptoms of bad knock sensors and one of them was surging under load (when my surging happens). So I spent the better half of today replacing those stupid sensors, all seemed good, then after a few minutes of driving I floor it up a bridge and it started surging again... I really think its something to do with fuel/air and electronic related it seems to happen intermittently or after the truck is warmed up. My other thought was maybe torque converter but my transmission shifts really smooth. The TC went out on one of my old cars and it through a code and the trans shifted like doo doo. I know there is still stuff to check..coil packs, maf, other sensors related to fuel and air. I'm posting to see if anyone else has had a similar issue and fixed it.