2012 gm engine swap. no start. remove security feature.
2012 gm engine swap. no start. remove security feature.
Can't really say without a data log and tune file.
If VATS was removed with a write entire, then the security system won't be the cause.
2016 Silverado CCSB 5.3/6L80e, not as slow but still heavy.
If you don't post your tune and logs when you have questions you aren't helping yourself.