I have been recently hearing a lot of talk about Gasoline Direct Injection (GDI) engines building up carbon really bad after about 30k-75k miles and my GDI engine has 113k. I never noticed my car (Impala with the 3.6L V6) was direct injected till I lifted up my hood and at the engine cover and it stated clear as day, direct injection. I’ve saw pictures/videos of Ford’s/Kia’s/Hyundai’s with about 75k miles with the GDI engine carbon’d up, I’m not sure if mine has this problem but if so what are some SAFE solutions to get rid of it? (I’ve heard some solutions can clog up the Catalytic Converter.) I haven’t seen a Chevrolet dealer that offers a cleaning service, only other brands. I change the oil frequently, drive mostly highway, and only Top Tier Fuel. The only thing that I do wrong is excessively idling all the time.