If you have over 25K on your plugs they could be the problem. Yes a pound & a half can be enough to cause a misfire if your car was already near the edge.
I run a custom map 6 & ramped up 1/2 pound at a time with Terry reviewing the logs. Got to bad logs then backed down 1/2 pound.
2017 CX-5 - 2016 Genesis R-Spec Coupe - 2014 435M-Sport MPPK/MPE - 2013 135is Cab 6MT/JB4 - 2009 V-Star - 2009 Expedition 4X4 - 1998 Ranger 4X4 - 1965 Cobra MK-IV
Dyno Tuned 470WHP - First Start