[QUOTE=JWoody;408273]do the O2 sensor MV's swing high and low while idling?


most i seen was 0.850 and lowest i seen was 0.090. i also check MAF readings and im getting 0.90 lb/min at idle. only raises up to about 4lb/min under load.

 

I would have the exhaust leaks repaired prior to going any further to make sure this is not causing your issue.

as long as the MV's are switching back and forth then its doing what it should,
.90 lb/min is in the ballpark for the 6.0L at idle in park or neutral

can you see the injector pulse width on your scanner, if so are both banks close?

Looking at the wiring diagram the only common wire for the O2 sensors is the power wire, don't see how one sensor can effect the other through wiring.

if you can clear codes with your scanner then try unplugging the MAF sensor after cranking the truck, it will through a code but you can clear it. this will put the truck into speed density which will cause it to stop using the MAF for fueling. After unplugging the MAF look at the trims then and see what they do, pay attention to how the truck idles after unplugging the MAF.

Neal

 

with MAF unplugged the truck runs even worse. bogs and won’t get up to speed at all.

 

like i mentioned tighten your intake manifold bolts before going to crazy. and if you can check your fuel pressure.

 

Check this bulletin=>Fuel Trim System Lean