I dropped my 06 GMC sierra off to get 2 new belts and they recommended that I get the fuel injectors cleaned and the intake ??? I don't know what they clean exactly or how they do it. They called me an hour and thirty minutes later and said it was all done and the total was $535.00 That sounds a little expensive to me. If they only had it for and 1:30 I bet they poured some injector cleaner in the gas tank.