Lean stutter at WOT

[b00stedtalon2]

I've had this problem for some time now. Right now that car is at a steady 10.8 AFR at only 10lbs with the GT30R, stock ignition timing right now.

The car will randomly studder once I get to 10lbs if i'm in 90% + throttle (Pretty much hits a brick wall and sounds like my 2step except it doesn't build boost). Once in a while I will be able to get away with it not studdering but 90% of the time it does. When it studders the AFR goes CRAZY lean.

No boost leaks not like that will make it lean, brand new plugs and wires.

Any ideas will be appreciated, thanks!

 

[JDR7919]

Whats your fuel pressure set at?

 

[b00stedtalon2]

It shows 43 at idle, but the gauge is mounted inside the engine bay so I do not know what it is while i'm in boost.

 

[pneumo]

Rich misfires will show up as lean spikes on the O2/ wideband.
You need to lean it out gradually until the misfires stop.