hi recently put a timing belt on the car. sonata 2.4 204000 miles. car ran great for two days. felt belt was correct. had all the marks lined up . only mark not sure was rear counter shaft. it had a paint mark. there is also a small hole on the gear but didn't use that. two days later i went to start and it vibrated or had a miss. sounded throaty in the exhaust. also seemed to be from 1 cylinder.when i first installed the belt i rotated motor 6 times by hand to make sure all ok. fired it up and let it idle . was smooth as silk. i just took it all apart to see if marks were off. seemed ok. a week later i reinstalled the belt and again felt it was correct. turn over by hand no restriction. still had odd vibration. then check engine light came on. then it hardly moved. no power. checked plug in 1 cylinder and plug had oil and black soot. not sure if i damaged the crank position sensor. i also installed two new spark wires. coils i have to order . but i still cant explain why car ran good for two days . then on start up had vibration/miss any ideas ? i have no car at this point and parts are best ordered from where im at.