I have a 2017 GMC Sierra 5.3 4WD. I was getting a misfire on cylinder 6 code. I decided to do a AFM delete on the truck. I put the new camshaft and non AFM lifters in the truck and now the truck engine is smoking and running horribly then will turn off. There’s a long delay from when I turn the key in the ignition to when the engine starts. Is there any advice to help troubleshoot
Feelin your pain. That’s a pretty big expense to get such a bad result.
May just be that the ECU needs to be tuned. But I would definitely want a definitive diagnosis before you change anything else. Sounds like a job for an experienced mechanic with one of Scotty’s “fancy” scan tools.
Well so many things can go wrong. Taking an engine apart and changing the camshafts. Your head spin. I would start by doing a compression test of the engine to see if it's even physically sound now
