Coyote Gen3 rough idle at start then smooth

[edwardb]

Yeah, those are the codes if your CMCV valves are removed or not plumbed properly. The difference they make to how the engine runs are pretty subtle, to be honest. Tuning them out for our purposes is fine. Really doubt they would have anything to do with cylinders not firing. I'm assuming you have lockouts installed so they're fixed open? Hopefully Lund will help you out with this. You're doing a Lund tune at the go-kart stage? I expect you know their tune requires you to do extensive driving? They provide the profiles they want you to follow while running the data log. Up to and including wide open throttle hits once the tune gets close. I never started the tune processes on mine until they were complete, legal, and I could drive extensively (and legally). BTW, another first start with open headers. Don't see ear protection. That's hard on your equipment.