Today I just bought brand new RC SL9-440cc since I thought my RC SL4-440CC werent flowing right. I swapped them out with new Seals and O-rings. My old AFR was sitting at 13.4, and when I installed my New SL9-440cc Injectors its reading 20.1 AFR. I dont know why its so lean, they are the exact same injectors. I didnt mess with the Fuel Pressure regulator or anything, Just swapped out OLD for NEW, same 440CC. just one is for SL9 is made specifically for Honda, and SL4 can be made to fit other vehicles.
Please let me know. thanks.. Im tuning on Thursday and I really need to find out whats causing this.