Rick Cruz

Hello, Need help please trying to figure out my 2002 Suburban 5.3 with hard start and throws a code immediately code p0343 . I have replaced cam position sensor also tested power and ground on pigtail to sensor. fuel pressure is good about 50 psi and holds at like 48. I have read somewhere that the alternator may have something to do with it if it is bad. Charging system is good. Any help would be greatly appreciated