I'm interested in this too. Do you really have to remove the UIM or not?
I myself am very curious as to how you did this. Not saying I don't believe you; I really want to. The pictures posted earlier in this thread show how it's almost an impossibility to remove the 3 rear coil packs without having to remove the upper intake manifold, so if you can provide more details (and maybe more pics), that would be very, very helpful! I myself would like to get this done, so it would be awesome if you could provide some more detail.I've done 2 spark plug changes on my 2013 ltz lfx and you do not need to pull the intake. unplug the coil rotate the coil pack and there ya go. 6 plugs should take 25 mins flat. Don't use the spark plug socket with the rubber it just causes headaches. I used the appropriate size socket and a piece of paper towel wedged in place to install the plugs back in with ease. Best of luck
And don't waste your time with e3's for this motor ..ran like crap and started fartin at idle.