XMLHttpRequest cannot load http://localhost:8080/hvTool2_Ang2/src/app/php/pullData.php. Request header field content-type is not allowed by Access-Control-Allow-Headers in preflight response.

<IfModule mod_headers.c>
    Header set Access-Control-Allow-Origin: *
</IfModule>

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS');
header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token');

getData(routing: string, functionindex: number, dataarray) {
    var sentData = JSON.stringify(dataarray);
    var sentArray = [routing, functionindex, sentData];
    var returnedJSON;
    var url;
    if (this.dev_env == true){
      url = this.devPHPfolderURL;
    }
    else{
      url = this.prodPHPfolderURL;
    }
    let headers = new Headers();
    //headers.append('Content-Type', 'application/json'); //CORS issue
    headers.append('Content-Type', 'text/plain'); //no CORS issue

    return this.http.post(url, sentArray)
        .subscribe(
            result => returnedJSON = result,
            () => console.log("Failed..."),
            () => console.log("Completed: " + returnedJSON)
        );
  }

$myServer = "SERVER"; //Actual variable answers were changed for this post.
$myUser = "USER";
$myPass = "PASS";
$myDB = "DATABASE";

// connection to the database
$connection = odbc_connect("Driver={SQL Server};Server=$myServer;Database=$myDB;", $myUser, $myPass) or die("Couldn't connect to SQL Server on $myServer");
$result = odbc_prepare($connection, $query);
odbc_execute($result)or die(odbc_error($connection));
odbc_close($connection);
odbc_fetch_array($result);

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: GET, POST, PATCH, PUT, DELETE, OPTIONS');
header('Access-Control-Allow-Headers: Origin, Content-Type, X-Auth-Token');

while ($info = odbc_fetch_array($result)) {
   $total[] = $info;
}

echo json_encode(odbc_fetch_array($total); //To send to JavaScript

headers.append('Content-Type', 'text/plain');

headers.append('Content-Type', 'application/json');

this.reqOpts = { headers: { 'Content-Type': 'application/x-www-form-urlencoded' }};