Unfortunately, it is not possible to clean the valves with fuel additives with direct injection (DI). regards...I have a friend with a 2016 pilot. I was worried things like this may happen since they switched to direct injection in 2016 from the previous multi port injection. With the injector face directly in the cylinder running against the high pressure combustion environment in the cylinder is extreme environment for possible problems. I was going to suggest she plan to run some fuel additive on occasion and an intake treatment like Seafoam every 5K or 10K to help keep the valves clean.