Add Custom Fields to Default Wordpress Search

function custom_search_where($pieces) {
    // filter to select search query
    if (is_search() && !is_admin()) {
        global $wpdb;
        $custom_fields = array('your_custom_field', 'your_other_custom_field');
        $keywords = explode(' ', get_query_var('s'));
        $query = "";
        foreach ($custom_fields as $field) {
             foreach ($keywords as $word) {
                 $query .= "((mypm1.meta_key = '".$field."')";
                 $query .= " AND (mypm1.meta_value  LIKE '%{$word}%')) OR ";
             }
        }
        if (!empty($query)) {
            // add to where clause
            $pieces['where'] = str_replace("(((wp_posts.post_title LIKE '%", "( {$query} ((wp_posts.post_title LIKE '%", $pieces['where']);
            $pieces['join'] = $pieces['join'] . " INNER JOIN {$wpdb->postmeta} AS mypm1 ON ({$wpdb->posts}.ID = mypm1.post_id)";
        }
    }
    return ($pieces);
}
add_filter('posts_clauses', 'custom_search_where', 20, 1);

/*
** Code from:
** http://wpdevsnippets.com/extend-search-include-custom-fields-without-plugin/
*/

// ******************************************************
// IMPORTANT: prevent duplicate posts being returned
// ******************************************************
function websmart_search_groupby( $groupby ) {
        global $wpdb;
        if( is_search() && !is_admin()) {
                $groupby = "$wpdb->posts.ID";
        }
        return $groupby;
}
add_filter('posts_groupby', 'websmart_search_groupby' );

/*
** Code from:
** http://websmartdesign.co.nz/searching-structured-post-data-with-wordpress/
*/