Welcome. You can certainly ask, but we're not experts on that engine. I assume you have a code like P030X where X points to the cylinder the PCM thinks has a misfire? I would search for a Caddy-specific forum. I see cadillacforums.com claims to be a big one, but they're owned by Vertical Scope, the greedy Toronto company who bought and ruined our old hangout, Trailvoy. Sneaky VS is even trying to conceal their ownership of cadillacforums.com. They also own Cadillac-ELR.com, CadillacATSForum.com, CadillacOwners.com. Sigh. I would shun them, but that's just me.