So got a CEL the other day after a nice 300+ mile trip, had no issues besides a nail in the tire. So just got the code scanned and codes p0327 and p0011 came up. So did a little research and found a sub harness should be replaced as well as the knock sensor. So found the z1 sub harness $35 so set as far as that part but had a couple questions while having the top off anyway.

what knock sensor did everyone purchase? $110 cheapest i found for oem but thats a big hit right now.

Also i'm approaching 120k miles any gaskets i should change while i'm in there??

Also i remember reading that if my drivers side spark plug had oil on it when i took it out that the seals were most likely worn, is this in the same vicinity as the work that will need to be done for the knock sensor so i can get that out of the way??

also any other sensors or issues that i should start worrying about??

i've had the car since 107k miles and had ticking sound which everyone says is normal for our model cars so havent really been to worried.

And last but not least tranny fluid, always hear the stories of changing fluid and tranny gets shot any issues with our cars with this?? i myself haven't changed it but wanted to double check before i just jump right in, have done it for a trailblazer so shouldnt be to different.