Car has 58.5k miles. Before I took it to the dealership, I ran two tanks through with Techron Concentrate. Car doesn't show any diagnostic codes although dealership recently replaced thottle because they suspected that it was the problem. That didn't help. They also suggested that I clean injectors, and do an engine decarb. I cleaned the injectors and found SOME improvement. I don't want to continue down this path if it will not fix the problem. Do you recommend a decarb? What else could be causing the hesitation.