1. Check the fuel system. Do you have an adjustable FMU? If so, check the settings? (Do you have a fuel guage?) Can you tell us step-by-step what you did during your fuel system install? It seems from your description that your car is running poorly even off-boost and that shouldn't happen. You still have your stock FPR connected(STAR system), right?
2. Check the vacuum lines. If you have the STAR kit, you have that vacuum line that runs from the intake plenum back to the FMU, check that connection. (It may not be related to that however, if you're running poorly off-boost as well)
3. Look around your exhast manifold. How are the bolts there?
Again, much of this is hard to speculate on. Keep giving us descriptions of what's happening during your driving. Keep your radio off and listen carefully to your engine. Watch your rpm's and boost guage. What does the boost guage read under vacuum? (this is just as important) Maybe roll down your window and listen for a bit as well.
Try not to worry about what your boosted results are until you have your non-boosted driving results straightened out. Boosting is not a big deal if you can't get your normal driving conditions under control.
Good luck and drive carefully.
Jason 98' Eagle Talon ESi-T Mitsu Super 16g Turbo(HRC)
