There is a little problem with this. Our factory fuel pressure regulator dose not hook to the intake manifold for its vacuum reference, bot to the intake box. This means that it never sees a true vacuum. If anything it sees more vacuum with more throttle, which is the opposite of a regular regulator.
#1 solution is not too efficient. It is going to produce allot of inconsistency and variance in the O2 readings and trip the computer.
#2 is going to completely change all the mapping in the factory ECU. The larger tube will cause the car to run lean at idle, and trip the computer within 10 min of just idling. I saw this problem allot on the Celica forums when I had one.
Both of thies would work great if our cars wrn't so sophisticated.
I plan on experimenting a little with the fuel pressure regulator on my truck. Hooking the vacuum line to the manifold its self pre and post supercharger. Getting an adjustable regulator. All this as soon as get off my ass and put my wide band O2 on the truck and remember who I lent my fuel pressure test gauge to.
As for ECU options there are a few but not they