i installed a walbro 255 fuel pump and an adjustable fuel pressure regulator. I know now that the resistor box cannot be used with obd2 injectors or plugs which i have... would the resistor box be what is making my car idle and run rough?

 

Did you install a gauge when you put your pump/reg in? You'll need to adj your fuel pressure back to stock settings or at least what the ECU was tuned for if it's chipped/aftermarket.

Also running OBD-2 injectors WITH a resistor box will cause all sorts of issues. Bypass the resistor box or get OBD-0 injectors.

 

i bought the gauge for the reg. but its not installed because im having trouble finding an adapter so the gauge will fit ontop of the fuel filter. im running a stock ls ecu, how would i find the stock level.