Hi all  I have a yaris 1.33 dual vvti  EML light came on When put on the diagnostic it read the camshaft sesnsor has an issue I took the camshaft sensor out gave it a good clean and back in the light went off for abit then came back on But when i took to mechinec he said it may need timing chain car drives fine but at around 3000rpm it make a light metalic noise soo what do you guys think?