Misfires - need brainstorming 2011 L99

[SScylla]

Hi guys, lately i needed to get past the technical and failed because i have a lit MIL.
in the past i always had o2 sensor problems but from the last time ive read the fault codes, it seemed not to be the culprit.

instead the engine told me 2 things: low oil pressure (this is because i broke of the connector of the oil pressure sensor when installing a new manifold)
and multiple misfires.

i then took the coils + wires of my girlfriends SS and replaced mine with hers, the only cylinders which had misfires still were cylinder # 1, 4, 6 and 7.
#4 and #6 had so many misfires, the count meter quickly overflowed and started to count from 1 again.
occasinally i get a flashing mil, logical since the car doesnt want unburnt gas damaging the cat.

so, i ve switched the coils. sparkplugs and wires with a cylinder without misfires but to no avail.

i also opened the valve cover and checked the pushrods and rockers for wear, i found that #2 cylinder had excessive wear both in and outlet, aswell as #8 on the outlet.
i changed all "filed off" rods and rockers with new oem ones.

what have i already done to the car prior to that:
i got a ported 102mm throttle body, a fast 102mm lsxr manifold, ls7 lifters + trays, ls3 valley cover and blocked off oil tunnels to the afm solenoids, deactived afm/dod, removed all afm hardware remaining,
long tube headers, deactivated rear o2 sensors because i run 200cell cats instead of the 200+200 oem ones. i got my cars ecu mapped too.

i checked the ground connection from head to block and from block to chassis, it seems ok, havent measured resistance yet.
also, occasinally there is 1 or 2 misfires in the timeframe of about 1 minute on all other cylinders, but i deemed it normal, correct me if i am wrong.

so what am i missing here? i cant figure out what to check or to do next to get this dam'd mil light off.

thanks in advance!!

[SScylla]

kinda sad that nobody wanted to chime in so far..

i also crossswapped the injectors but the misfire didnt go away either.

i then came to the conclusion it has to be something mechanical. i suspect the valves not closing accordingly. the only way why this might be is because of the camshaft. what if the cam is faulty.
an engine tuner mapped my car 2 years ago and he "turned" the cam slightly for longer duration at all times. can it be that the cam phaser is worn out because of that??

would really appreachiate if someone could help me out here

[SScylla]

for anyone who had the same issues: after i deleted the L99 AFM/DOD, the last thing i left from the stock engine was the camshaft.
the rest was converted to LS3.
the Camshaft has smaller lobes on the AFM/DOD cylinders, compared to the other cylinders.

means, if you replace your collapsible AFM lifters with the solid LS7 ones for example, your hydraulic lifter is a tad too short overall. the pushrod isnt going to be pushed to its apex, the rocker then isnt going to be rocking as far down as it should. results into valves not opening properly / not entirely.

the car judges that as misfires and so the CEL will flash or burn.

end of story, get slightly larger pushrods installed on the AFM cylinders and youre set. or get different camshaft.

thanks again for the huge support on this forum, i was so happy everyone wanted to help me on that one.

[Joe.G]

Thank you for following up with the issue, So many people fix the issue but never come back to say what it was which doesn't help people who search for a similar issue. I am just seeing this post now

[SScylla]

hey Joe.G, yeah i hate that too.

also a quick sidenote, stock pushrods are 7.400" on the L99, the ones which made my engine go without CEL were 7.450" ones.
for anyone wondering with what i meant by "slightly larger pushrods"

[Batmanntexas]

Glad you got this figured out! Going forward, if you have mechanical issues, start a post in the 'Camaro V8 LS3/L99 Engine, Exhaust, Bolt-on' thread. You will get a lot more response there.

-Scott