KTuner.com

After reflashing my step father's 2018 Accord 2.0t Touring, the car had a sluggish turn on. All the normal error codes came on, and then I saw a transmission code came on. I never seen that on my accord and I reflash mine to make my changes a lot. I went off and drove around the block and the car drove very sluggish. Error codes didn't disappear and that transmission code was still there as well. I turned the car off and then turned it on again. This time it turned on normally, but still drove sluggish. Error codes were still there. I ended up reflashing the car back to stock and everything went back to normal as it should. Why would this happen or am I doing something wrong?

Side Note:
I flashed the car with the stage 2 dual tune 1(Factory boost target in eco)
Car is the 10spd automatic

I'm not really sure what you mean here and you didn't mention an actual error code number so we're just left guessing. Feel free to reach out to support by email.

There was no code. It just said "Transmission System Problem. Performance may be reduced. See your dealer." It seems the car went into limp mode after I tuned it. Bringing it back to stock tune, allowed it to run normal as before.

Feel free to reach out to support by email.