Timing Problem

Hey hello I’m first time using this new program and so far looks like is real people talking. 

I have this Caravan in my bay is has been in 2 different shops, the first one done all timing parts because timing chain noise went they finished the job car was running but had a SES ON with a corretation code P0018 so they referred to different shop but this shop just replaced more parts, and can’t fix the issue so customer send it to me 

Car is running fine has no good performance but is drivable, idles fine has a code P0018 Crackshaft Position-Camshaft position correlation bank 2 sensor 1 

First thing that I did is check timing marks they looks ok everything is new at the bank so I don’t get it why has this code, I have a lab scope but I’m lost because one cam sensors Read 2 camshaft so I think I need more than 4 channel lab scope and also, I can’t find a good wave for to compare with! 

So I’m trying to find som help in this group may some one had a problem like this one? Or can somebody give me a advice to how can I hook my 4 channel lab scope ? 

If someone can give me a better idea i be appreciate thank you