lean-to-rich instantly

[exiletalon]

my PLX wideband shows, at idle, I am completely lean, but from 2000+, I go instantly rich.
At first I thought that it was my o2 sensor, but after replacing the sensore, teh and having a shop reinstall a new PLX comp., and new plugs, and checked for leaks, and everything, I dont understand why it still says that, even my crappy A/F gague, goes lean- straight to rich.

I have a ported: FP18G, EVO3exh.man., EVO3 o2 housing, FMIC, 2.5" intake/intercooler piping, 3"turbo back, SAFC2, 10psi, 91 pump. decent tune.
I am still on 450cc, I am afraid to upgrade to my 650cc, if I am going rich on my 450's.

I cant turn up the boost until I install and retune with my 650's, so its like a damn upgrade "wall".

 

[exiletalon]

any insight on this idea would help, similiar experiances are great also.

 

[CanadianTSi]

How rich?

The stock ECU shoots for 9.5/1 at WOT...

 

[exiletalon]

it goes from lean to very rich, I dont know exactly how rich, but is rich enough to foul my NGK's in 3 DAYS!!!!, but it is so lean at idle, that it is rough.