I'm new to this forum discussion world but I don't know where else to turn with this Enclave it's a FWD 09 Enclave with 115,000 miles I bought it as whole sale from a dealer because my family needed a vehicle with third row and we didn't have a lot of money to buy a good Craigslist car. I know whole sale was probably not the best way but it was the only way but I'm now having a problem I can't figure out as I cruise down the road at different speeds doesn't matter if I'm doing 25 or 65 it will hesitate and stumble if I release the pedal or give it a little gas it will go away until I settle back to keeping the pedal where it needs to be to stay at the designated speed I want. I have replaced the coils and plugs along with the tps and still does it now I'm lost and I don't really have the money to have a shop run threw it or the time to not have a car it's our families way of travel along with the car I respond to call for the fire department. Where should I look next? Ecu update? Torque converter?