have a p011 code is this the cam sensor and what does it consist of in replacing on 2002 Nissan Altima

car makes a knocking noise

Asked by for the 2002 Nissan Altima
2 answers
ck oil level 1st this is very common whn oil is low or dirty
Along with answer #1 , maybe have 'knocking noise' diagnosed if oil level is okay.May be faulty t-belt tensioner ,or other internal engine problem , making the cam sensor code a secondary issue.