maxpsi

I recently went to the track and noticed my fuel pressure was at 39psi as opposed to normally being at 46psi when at idle. My times are usually consistent being around a 13.4?@108.??, but I recently have only been able to run 13.5?@107.??. The only thing I can think of that I have done is removed the little emissions connection from the fuel rail (fuel vapor vent). As far as fuel, I run DSM450s cleaned, Walbro 255lph in tank, stock FPR, stock fuel rail, B&M FPG, and controlled by Hondata S200B. I checked my FP today, and it is at 46psi when at idle. Now I tuned on the dyno @ 10psi and made 271HP with my setup. Recently, I have been running 110 leaded and pushing about 11psi (prolly close to 300WHP). Could the fuel pressure drop I see be due to the injectors getting close to their limit? Should I buy a FPR?

Help would be much appreciated.