Had 2 questions for the fuel pressure regulator?
 

I been trying to test out my FPR, by driving my f4i at lower rpm's around 5,000 . Just to see what fuel mileage I get. I been getting around 35 mpg, is that good or should i change my FPR. Also sometimes at a red light when im going to take off it kinda sputters for a while.

The other question is where can I buy the FPR the artermarket one not from the dealer?

If you are getting 35+ mpg crusing at 5k rpms than your FPR is probably in good shape. The 5k cruising would suggest that you are taking it 10k+ between shifts. Generally speaking, this type of riding is consistent with your fuel economy.

As far as I know, (someone with more expertise correct me if I'm wrong), an aftermarket FPR should only be used with certain aftermarket injection upgrades. That being said, a stock FPR would be your best bet for replacement if you see the need to change it. You don't have to go through your Honda dealer to get one... search the net and you can find alot better pricing.

aight guys today I tried it out. My reserve lights came on
And I went to pump it got full with 2.76 gallons with 120 miles
so I think I am getting like 45 mpg. So shouldn't replace my FPR.

please somebody awnser this question. been wanting to know if I need to change my FPR?

If your gas mileage is that good and there's no lag in your throttle response across the powerband you do not need to replace it. Sounds like its in fine working order.