Convert array to CSV and force download

I'm trying to convert an array of products into a CSV file, but it doesn't seem to be going to plan. The CSV file is one long line, here is my code:

for($i=0;$i<count($prods);$i++) {
$sql = "SELECT * FROM products WHERE id = '".$prods[$i]."'";
$result = $mysqli->query($sql);
$info = $result->fetch_array(); 
}

$header = '';

for($i=0;$i<count($info);$i++)  
  {
    $row = $info[$i];

    $line = '';
    for($b=0;$b<count($row);$b++)
    { 
    $value = $row[$b];                                      
        if ( ( !isset( $value ) ) || ( $value == "" ) )
        {
            $value = "\t";
        }
        else
        {
            $value = str_replace( '"' , '""' , $value );
            $value = '"' . $value . '"' . "\t";
        }
         $line .= $value;
        }
    $data .= trim( $line ) . "\n";
}
$data = str_replace( "\r" , "" , $data );

if ( $data == "" )
{
$data = "\n(0) Records Found!\n";                        
}

header("Content-type: application/octet-stream");
header("Content-Disposition: attachment; filename=your_desired_name.xls");
header("Pragma: no-cache");
header("Expires: 0");

array_to_CSV($data);


function array_to_CSV($data)
    {
        $outstream = fopen("php://output", 'r+');
        fputcsv($outstream, $data, ',', '"');
        rewind($outstream);
        $csv = fgets($outstream);
        fclose($outstream);
        return $csv;
    }

Also, the header doesn't force a download. I've been copy and pasting the output and saving as .csv

Instead of writing out values consider using fputcsv().

This may solve your problem immediately.

Note from comment: I should mention that this will be making a file on your server, so you'll need to read that file's contents before outputting it, also if you don't want to save a copy then you'll need to ùnlink`the file when you are done