Car: 03 ls 3.9l 55.6k miles Issue: Once car warmed up, surging and engine or tranny shake over 40 mph. In neutral / park, will not rev above 3k rpm. Will achieve 60+mph but can feel sputter or surging. Recent maintenance: (1) Just did a tranny pan drop replacing the filter and 6 its of fluid. First drive after that work. Was okay until she warmed up. (2)New plugs 50 miles ago. (3) New fuel filter. (4) New serpentine belt. Plus lots of other stuff pretty much unrelated to motor but no sign of an issue after 2 thru 4 were done. Coils: #7 replaced 41,635 mi on 10/15. #8 replaced 42,742 mi on 10/16. #2 & #5 replaced 51345 mi on 1/18 There is no check engine light on. Can codes be thrown without a warning light on these cars? I guess I need to run this by a shop to scan for codes. If it's another coil, should I just replace all coils to start a fresh base line using FoMo DG529? Car is new to me so I don't know what a bad coil feels like. I do have the maintenance records from new.