# Java 7, 138 bytes

 boolean c(int[]a,int s){String r="";for(int l=a.length,i=0,j;i<l;i++)for(j=-1;++j<l;)if(i!=j)r+=(a[i]+a[j])+",";return r.contains(s+",");}

**Explanation:**

 boolean c(int[]a,int s){ // Method with integer-array and integer parameters and boolean return-type
 String r=""; // Temp String
 for(int l=a.length,i=0,j;i<l;i++) // Loop (1) over the input array
 for(j=-1;++j<l;) // Inner loop (2) over the input array again
 if(i!=j) // If the index of both loops aren't equal (so not the same item in the list)
 r+=(a[i]+a[j])+","; // Append the sum with a comma to the temp-String
 // End of loop (2) (implicit / single-line body)
 // End of loop (1) (implicit / single-line body)
 return r.contains(s+","); // Return whether the temp-String contains the given sum (+ comma)
 } // End of method

**Test code:**

[Try it here.](https://tio.run/nexus/java-openjdk#jZBBbsMgEEX3OcXUKxATq9hOWolyhK6ytLwgrpNgEYgAt6oszp7aTrutrL9AmvmP@TOtUSHA@7gBCFFF3cL96JzplIWWaBvrRuH0QKDjIXptz@BllomT83MXjFS56ew5XlDLZ@yFfjNCM0ZnQy@3XDDWTyWqT0Q/yZ56JomqdcNU3TeUZZgJ38XBW/B562xU2gYS5joV6Q5wG45mCvWb7dPpD7hOHvIIUzeg6Jwd4PAdYnfN3RDz29SKxpKW2O4LliVGjgWWWOEO9wk5p1SsoSosSnzlLxVWBW55wmotWSBftCuxmLDV1KL/gXVfcfxTmbBcOX@5UML9w5426f4D)

 class M{
 static boolean c(int[]a,int s){String r="";for(int l=a.length,i=0,j;i<l;i++)for(j=-1;++j<l;)if(i!=j)r+=(a[i]+a[j])+",";return r.contains(s+",");}
 
 public static void main(String[] a){
 System.out.println(c(new int[]{1,2,3,4,5,6},11));
 System.out.println(c(new int[]{4,23,8174,42,-1},41));
 System.out.println(c(new int[]{2,1,1,1,53,2},4));
 System.out.println(c(new int[]{2,2,2,2},4));
 System.out.println();
 System.out.println(c(new int[]{1,1,1,1,1,3},3));
 System.out.println(c(new int[]{3,4,5},6));
 }
 }

**Output:**

 true
 true
 true
 true
 
 false
 false