Ok, so your in RTP and I'm right off 70, one block shy of Duraleigh Rd. Why not drop in and show me exactly what your problem is. Normal fuel head complaints are leakage, skips or bad stumbles. Most bad idles are vacuum leaks, bad/dirty injectors or CO adjustments. However, coils, EZLs and sticking egr valves will also cause 'em. On rare occassions you'll find a M117 with a guide walking in a head causing a intermitent skip and piss poor idle when not skipping. (these are also hard as hell to get a firm diagnosis on)
What I'd like to know is what the base duty cycle readings are and O2 response times. Drop in, we dont bite.
Joe