lean, but why?
 

ok, so my exhaust manifold had cracked some welds and the dp to the rest of the exhaust flange was leaking. fixed both of those. also did a diy dual feed fuel rail, now im running lean. with exhaust leaks my wideband showed 10.0 afrs, (i was tuned to 11.0 up to near redline, then 10.0 for the last couple hundred rpms) now when icross the zero threshold and go a tad into boost, my afrs stay around stoich. so obviously i back off. any suggestions?

running a greddy emu, begi rrfpr, and fm o2 clamp. once again, it was fine before i effed with it.

Did you get chunks in your fuel rail causing a blockage?

i took my time and used grease on the drill bit. but i s'pose its still a possibility.

That would be the first place i looked too. Check the injectors themselves. Even debris from old gas can clog them up. Too bad you don't have individual EGT's or else you could see if it was only affecting one cylinder.

yeah, that would make it easier to diagnose.

Since you fixed your cracks does it spool faster? You may be hitting higher boost per cell earlier which could throw it off. But at some point it should be back to rich when the boost levels.

My car with ms had Some variation when I changed the exhaust out. Don't ask me why though.:dunno:

another good possibility. i think i have major boost leaks tho. hopefully testing it soon.