diff --git a/conn.go b/conn.go
index d938edc8..1609344e 100644
--- a/conn.go
+++ b/conn.go
@@ -614,23 +614,6 @@ func (c *Conn) CauseOfDeath() error {
 	return c.causeOfDeath
 }
 
-func (c *Conn) sendSimpleQuery(sql string) error {
-	if err := c.ensureConnectionReadyForQuery(); err != nil {
-		return err
-	}
-
-	buf := appendQuery(c.wbuf, sql)
-
-	_, err := c.pgConn.Conn().Write(buf)
-	if err != nil {
-		c.die(err)
-		return err
-	}
-	c.pendingReadyForQueryCount++
-
-	return nil
-}
-
 // fatalWriteError takes the response of a net.Conn.Write and determines if it is fatal
 func fatalWriteErr(bytesWritten int, err error) bool {
 	// Partial writes break the connection
diff --git a/query.go b/query.go
index 1c105df5..ec48db9b 100644
--- a/query.go
+++ b/query.go
@@ -9,7 +9,6 @@ import (
 
 	"github.com/pkg/errors"
 
-	"github.com/jackc/pgx/internal/sanitize"
 	"github.com/jackc/pgx/pgconn"
 	"github.com/jackc/pgx/pgtype"
 )
@@ -519,30 +518,30 @@ func (c *Conn) buildOneRoundTripQueryEx(buf []byte, sql string, options *QueryEx
 	return buf, nil
 }
 
-func (c *Conn) sanitizeAndSendSimpleQuery(sql string, args ...interface{}) (err error) {
-	if c.pgConn.ParameterStatus("standard_conforming_strings") != "on" {
-		return errors.New("simple protocol queries must be run with standard_conforming_strings=on")
-	}
+// func (c *Conn) sanitizeAndSendSimpleQuery(sql string, args ...interface{}) (err error) {
+// 	if c.pgConn.ParameterStatus("standard_conforming_strings") != "on" {
+// 		return errors.New("simple protocol queries must be run with standard_conforming_strings=on")
+// 	}
 
-	if c.pgConn.ParameterStatus("client_encoding") != "UTF8" {
-		return errors.New("simple protocol queries must be run with client_encoding=UTF8")
-	}
+// 	if c.pgConn.ParameterStatus("client_encoding") != "UTF8" {
+// 		return errors.New("simple protocol queries must be run with client_encoding=UTF8")
+// 	}
 
-	valueArgs := make([]interface{}, len(args))
-	for i, a := range args {
-		valueArgs[i], err = convertSimpleArgument(c.ConnInfo, a)
-		if err != nil {
-			return err
-		}
-	}
+// 	valueArgs := make([]interface{}, len(args))
+// 	for i, a := range args {
+// 		valueArgs[i], err = convertSimpleArgument(c.ConnInfo, a)
+// 		if err != nil {
+// 			return err
+// 		}
+// 	}
 
-	sql, err = sanitize.SanitizeSQL(sql, valueArgs...)
-	if err != nil {
-		return err
-	}
+// 	sql, err = sanitize.SanitizeSQL(sql, valueArgs...)
+// 	if err != nil {
+// 		return err
+// 	}
 
-	return c.sendSimpleQuery(sql)
-}
+// 	return c.sendSimpleQuery(sql)
+// }
 
 func (c *Conn) QueryRowEx(ctx context.Context, sql string, options *QueryExOptions, args ...interface{}) *Row {
 	rows, _ := c.QueryEx(ctx, sql, options, args...)
diff --git a/replication.go b/replication.go
index 8d67db85..21d9a3d8 100644
--- a/replication.go
+++ b/replication.go
@@ -330,41 +330,6 @@ func (rc *ReplicationConn) WaitForReplicationMessage(ctx context.Context) (*Repl
 	return r, err
 }
 
-func (rc *ReplicationConn) sendReplicationModeQuery(sql string) (*Rows, error) {
-	rows := rc.c.getRows(sql, nil)
-
-	if err := rc.c.lock(); err != nil {
-		rows.fatal(err)
-		return rows, err
-	}
-	rows.unlockConn = true
-
-	err := rc.c.sendSimpleQuery(sql)
-	if err != nil {
-		rows.fatal(err)
-	}
-
-	msg, err := rc.c.pgConn.ReceiveMessage()
-	if err != nil {
-		return nil, err
-	}
-
-	switch msg := msg.(type) {
-	case *pgproto3.RowDescription:
-		rows.fields = rc.c.rxRowDescription(msg)
-		// We don't have c.PgTypes here because we're a replication
-		// connection. This means the field descriptions will have
-		// only OIDs. Not much we can do about this.
-	default:
-		if e := rc.c.processContextFreeMsg(msg); e != nil {
-			rows.fatal(e)
-			return rows, e
-		}
-	}
-
-	return rows, rows.err
-}
-
 // Execute the "IDENTIFY_SYSTEM" command as documented here:
 // https://www.postgresql.org/docs/9.5/static/protocol-replication.html
 //
@@ -376,7 +341,8 @@ func (rc *ReplicationConn) sendReplicationModeQuery(sql string) (*Rows, error) {
 // type names, so the field descriptions in the result will have only
 // OIDs and no DataTypeName values
 func (rc *ReplicationConn) IdentifySystem() (r *Rows, err error) {
-	return rc.sendReplicationModeQuery("IDENTIFY_SYSTEM")
+	return nil, errors.New("TODO")
+	// return rc.sendReplicationModeQuery("IDENTIFY_SYSTEM")
 }
 
 // Execute the "TIMELINE_HISTORY" command as documented here:
@@ -391,7 +357,8 @@ func (rc *ReplicationConn) IdentifySystem() (r *Rows, err error) {
 // type names, so the field descriptions in the result will have only
 // OIDs and no DataTypeName values
 func (rc *ReplicationConn) TimelineHistory(timeline int) (r *Rows, err error) {
-	return rc.sendReplicationModeQuery(fmt.Sprintf("TIMELINE_HISTORY %d", timeline))
+	return nil, errors.New("TODO")
+	// return rc.sendReplicationModeQuery(fmt.Sprintf("TIMELINE_HISTORY %d", timeline))
 }
 
 // Start a replication connection, sending WAL data to the given replication
@@ -416,8 +383,12 @@ func (rc *ReplicationConn) StartReplication(slotName string, startLsn uint64, ti
 		queryString += fmt.Sprintf(" ( %s )", strings.Join(pluginArguments, ", "))
 	}
 
-	if err = rc.c.sendSimpleQuery(queryString); err != nil {
-		return
+	buf := appendQuery(rc.c.wbuf, queryString)
+
+	_, err = rc.c.pgConn.Conn().Write(buf)
+	if err != nil {
+		rc.c.die(err)
+		return err
 	}
 
 	ctx, cancelFn := context.WithTimeout(context.Background(), initialReplicationResponseTimeout)