Originally Posted by Geoland1st
Did you ever get this issue solved? I have a 2002 elantra that also throw p0340 every once in a while. It also has a rough idle. I have done a lot of the steps that you have, including taking those same pictures of the camshaft chain alignment. I also have opened up one of my other elantras and compared the camshaft chain alignment and I don't see any difference.
Thread is 7 years old......and nobody posts here any more. I just happened to log on today for the first time in like 3 months.......good luck