I was under the impression that at WOT the ecu uses predetermined fuel pulses per maf reading and ignores what the 02 is sensing. The ecu cannot compensate for changes if the airflow is too different as it's no longer using the 02 sensor to see a lean condition. Could be wrong though

 

I recently did a few dyno runs while installing my mods in a couple of steps.

-dyno
-header, tp, exhaust
-dyno (loss power)
-afr adjustment
-dyno (gained power)
-air intake, spacer, mrev2
-dyno (loss power again)
-afr adjustment
-dyno (gained power)
-uprev tune
-dyno (gained power)

In every instance where i loss power i was running lean.

 

wow wierd but i see hwo its true,

well anyone out there with the same car n mods i have got any info to throw in, n my sig has all my mods, thanks