If you're going to do the carbon cleaning on the valves, make sure you take out all the injectors and have all the injector tips cleaned of carbon buildup as well. I know most will let the injectors stay in the block if they don't come out with the manifold but give yourself the peace of mind and have those cleaned as well.
I had my carbon cleaning done at 65k miles by a friend that works at a stealership but 15,000 miles later I was experiencing all the symptoms you're experiencing plus the engine just shutting off whenever I would throw the car into neutral on a cold winter morning. Knew it was a fuel system related issue and started looking into high pressure fuel pumps, low pressure fuel pumps and the fuel control module on top of the gas tank as possible suspects. Didn't have $600 laying around for a shop to do another carbon cleaning or to buy any of the parts I mentioned so I decided to do it myself. Everything went smoothly and all my injectors happened to come off with the manifold. Turns out the two injectors that stayed in the block during the first carbon cleaning when done by the stealership were caked with carbon. So much so that you couldn't see the tiny holes from where the fuel was suppose to be injected. Cleaned the valves, all the injectors, replaced the seals and manifold gasket and she's like a brand new car. Now to have the timing chain service done and that pesky tensioner replaced.
TLDR; Clean your injectors even if they stay on the engine block. You'll thank me later.