lq4 6.0 misfires?

['09SS]

2003 express van 6.0 i just picked up has a few issues i can't seam to figure out. in am attaching a log file. cylinder 1 and 6 have constant misfires i have already did plugs old ones looked fine, wires, fuel filter, mas cleaning, seafoamed intake and fuel. 6 was worse so i changed the coil pack to but the same problem exists. is there anyway to tell if the injector is shot on 1 and 6? or log fuel injector duty to see if its maxed out?

['09SS]

van is stock, torque management removed. file from pcm is in this link http://www.hptuners.com/forum/showthread.php?t=28037

['09SS]

190k on it but it runs good besides the misfire, seams to only misfire at idle where i can see it in the scanner and part throttle on highway where i can also feel it. wide open doesnt feel like it is misfiring. the fuel filter has just been done, what do you mean by cylinder balance? leakdown test?

['09SS]

adding a few more logs still chasing down this problem, would bad o2 sensors cause idle- low load misfires? i'm ruling out the cats because high load the van runs fine and does not feel down on power. i would think a plugged cat would be more of an issue during high load not low.

[miker2]

i transplanted a lq4 into my 2000 suburban and added z6 cam shorty headers and a radix.i can drive for months with no codes ,including short xway trips (5 to 10 miles).but if i take an extended xway trip ,it'll throw a misfire code.

['09SS]

i checked cats with gauge no pressure difference in or out of either cat, did intake manifold gasket, dunno if it was shot but alot of the actual gasket material was flush to the frame of the gasket assembly on the old one. still was having problems ended up doing cylinder balance all were good, did crank relearn and this fixed the misfires on 1 and 6. i ended up doing the o2 sensors a few weeks later one of them was giving lazy readings causing computer to pull fuel so much that it caused bad misfire eventually while idleing.