A name such as Enojarvi could be misspelled many ways, making it hard to find him in the census.Keep in mind that there was an influenza epidemic in the United States 1918-1919 and Elmer's parents may have died then.
I believe this is his uncle John, with whom he was living in 1920:
Death record of Finns who died in King Co., Washington: John Enojarvi, b. 20 Jun 1865 Finland, d. 22 Oct 1938, in hospital Seattle, WA, father Andrew, mother Annie (maiden name not given).Died of heart disease.Marital status: Single.Occupation: Laborer. Body released to go to Kent, WA.
You might Google and find a library in Kent, WA.Contact them to see if they have obituaries from 1938 or if they can tell you where to find them.There might be info about Elmer in the obit.