Good clue on the cold start KR.
sounds like the sensors are hearing mechanical noise.
You can turn down the sensitivity in the tune.
Are the sensors real GM parts?
might check to make sure they were torqued properly.
The case relearn relies on the rev limiter in neutral. Perhaps it got raised?

What year and type type of car?

maybe post your tune.

Ron

 

Thanks for all the replies gents but it looks like I have trashed a lifter. I took the rockers off today they look fine other than a little ware on the tips. The valve springs and push rods look perfect so it looks like the heads are coming off. Big shame as the motor only has 5000 miles on it. I will be having a little chat to my engine builder when he gets back from the Xmas break to see what he thinks.

If anyone is interested they are new ls7 lifters in factory buckets

 

Let us know how it comes out.

 

An improper build or immediate part failure could completely explain your false knock issues. I would have several words with the engine builder. Just don't kill him until after you find out who he got the parts from. A lifter doesn't trash itself without help.