550cc Injector help please

[7mgangsta]

I have been running lean for some time now, I've done everything I can think of to richen my A/F ratio, but I'm stuck. Today I found that the 550cc injectors that I put in are low impedance and call for a resistor box, which of course did not come with them when i bought them.
http://www.precisionturbo.net/fuelsystems.php I have the Mitsu style 550's
Before lean::: Installed some mods, I street tuned it, the car ran decent for a day then I took it for a pull up to about 120 and it all of a sudden started to run lean.
ANY ADVICE?

 

[hvyman]

What are your mods?
What are you tuning with?
What are you watching your afrs with?
DO you have a upgraded fuel pump?


7m has a resistor box stock.
No injectors come with a resistor pack. Have to do that one your self.

 

[M_31_07]

You have a 7M right? If so, you already have the factory resistor box.

 

[7mgangsta]

7mgte, ct26, 3" hardpiping w/3" al intercooler, 550's, lexus afm, walbro 255 with fuelab afpr w/gauge, fuel damper bypass, aem wideband, APEXi SAFC. (It's idling at 16 and under boost at 12.5) only lean under boost. Well, looks like it's not the injectors then... I did find that the injectors I'm running call for a 43.5 psi and I've been running 30 with vac and 40 without vac. I was thinking maybe the vac itself wasn't functioning properly. My buddy said it might be the ecu. I unplugged the o2 sensor and it started idling at 13.5... I just don't know what to do about it.