2001 Chevrolet Blazer timing

Initially one day my car started cutting out and bucking and wouldn't drive over 15mph. I got it home and reved it up and it died and wouldn't start again. I thought it was a bad catalytic converter so I removed them and still no fix. There was no code. I replaced the crankshaft sensor and reset computer, then it would then start then dies. I then unplugged the maf and it would start and run. I put a new maf and decided to replace the o2 sensors. After that it started and ran but terribly and I could tell there was a bad timing issue. Finally I got a code p1345. I thought then I needed a relearn. I had a guy come over and look at it and he said that these don't need relearns and messed with the distributor and crank and said it was out of line and he lined it up and then started it and it wont start again. He said I needed a new timing chain. What do u think any ideas?