Working on getting my newish to me "well maintained" ZHP up to snuff, and currently chasing down lean codes and misfires, and trying to figure out if I need to go in the fuel direction or vacuum leak/intake direction. Main symptoms are persistent lean codes, and misc cylinder misfires that happen at WOT north of 4000rpms.
FWIW, coils, plugs are new new under my ownership. MAF, upper intake boot, misc vac lines, bank 2 cat, and DISA 0 ring were replaced under previous administrations. I've searched around here, E46fanatics, etc, and am still having trouble getting my head around this.
I watched a couple of 50skid videos regarding fuel trims, and here are my results (using a Foxwell NT510)
This is the first time I've dealt with attempting to diagnose with fuel trims. Any advice here would be appreciated! The car is a basket case at this point, so I'm looking forward to getting it running properly.