Dang. This sounds like the issue I had. Took me 3weeks, working on it every night to find the problem. It would stall under load. Idle was rough. At first it would back fire while coasting, then it got worse and would pop and sputter. I had no codes. I did the plugs and checked the coils with the SERVICE MANUAL that I would cram down the dealers throat. ( You can check the coils with an ohm meter. The Honda service manual tells you how to do it and gives the numbers within tolerance. And they should know that). I did the fuel tank drain and fuel pressure and even did a compression test because at times it seemed like it was designated to one cylinder. The plugs looked fine but one was Sometimes wet with fuel up the threads. I checked the stupid fuel injector wires everyone complains about. Finally while all the plastic was off. I used a long screwdriver like a stethoscope. Placing the end ontop of the fuel injector, I stretched over and turned the key to ACC and listened to how they clicked. One sounded very different than the other. One was clearly clicking faster and solid, the other was faint and faded. The dealer told me that's not possible, they are supposed to sound like that, it's normal, blah, blah. 2 hour round trip, and $76. I know the frustrations. I hope this helps.
