Thats good news,good luck

 

I bought a 99 police tahoe with a 5.7 vortec with 220XXX miles and i had the same problems code P1345 popped up and i messed with distributor and ended up getting a new one thinking it would fix the problem of the misfiring. I was wrong it helped slightly but no avail, I ended up putting the #1 cylinder to TDC lined up the mark on harmonic balancer with timing cover. with that done take cap off distributor and rotate the crank to see if there is slop in the timing chain. if the rotor move with crank at same time your ok there. if the harmonic balancer move a 1/2 inch before the rotor moves you need a new timing chain. It should fix your problem or atleast get you on the foot.