No matter what injection system your car has, it's subject to carbon buildup over time. Here are some ways to prevent and clean carbon buildup in your engine.

We explain why all gasoline engines, especially direct-injected engines, benefit from routine intake manifold, valve, and injector cleaning.

In engines equipped with GDI, highly pressurized gasoline is sprayed directly into the combustion chamber rather than being injected at lower pressure upstream from the intake valve.

“CRC GDI IVD® Intake Valve & Turbo Cleaner is proven to remove up to 46 percent of these power-robbing deposits after the first hour of use.

Consumer Reports has no financial relationship with advertisers on this site. The process of walnut blasting, which entails cleaning the intake manifold and valves of a car’s engine with a high ...