Regulators can work that way, leaning, but cant richen it at all, if the computer senses more pressure it will just shorten the pulse of the injector, no way around it, all cars are the same, you didnt get a "freak". You felt a difference most likely because you told your brain you did, on a dyno there would be likely no difference. Listen to the guys above, they know their stuff.

 

There is some good info here, but some could be interpreted incorrectly.

First an AFPR will hot help if the pump cannot maintain the pressure.... setting the regulator to 55 if the pump can only maintain 45 at full throttle will not help.

If the car is lean the AFPR will help if the pump can maintain the higher pressure.

Now for the clarification to the above posts:
The computer cannot recognize the fuel pressure only the o2 reading. If the engine is lean the computer will add fuel (increase pulse width) which can also be added at full throttle to compensate for a lean condition (such as low fuel pressure).

If the car is rich the computer will subtract fuel at part throttle (reducing BLM's below 128), but not at full throttle. Your full throttle long term BLM's will always be 128 or higher. Therefore the computer will remove the excess fuel added (by increasing pressure), but only at part throttle.

Hope this helps.

 

yeah i think it has