When running at idle or driving I get a whistling noise from intake area and light blue smoke from exaust also I do have a engine code driver side oxygen sensors both heated part low sercut and one sercut malfunction it runs good but got a bad idle that comes and goes and also I have a vacuum code here's my codes p0031,p0141,p0161,p0455 I'm gonna change plugs have had vehicle almost two years never changed them but where cleaned and gapped it has only 154,000 miles on it did have too fix wires on oxygen sensors found them melted but passenger side was too but no codes just driver side also exaust manifold studs starting to break got exaust leak on side that's saying good great truck so far lot of power in truck and decent gas milage

 

You have a leak in the intake somewhere.