HI, Ive never used forums before so im not sure how all this works, but im need of some help. I have a 1999 Chevy Silverado 1500 with the 5.3, its your pretty basic truck and only has 77k on the clock. For some reason its been having a random miss fire on and off. Like one day it fits itself then the next it runs rough. I did recently replace the spark plugs and plugs wires aswell as replacing my MAF sensor. And tried to find any vacuum leaks, I found a pretty small one that I fixed with a new hose. But still no fix. Ive tried the brake clean and spray near the vacuum hoses swell as the intake nothing. Im starting to run out of ideas and im thinking 02 sensors or maybe a fuel pressure sender. Any feedback good or bad would be appreciated. Happy Holidays!