Which engine is the 2000 ford focus se zetech dohc or you need to replace egr valve?

The 2000 Ford Focus SE came with either a Zetec 2.0L DOHC or a Zetec 1.8L DOHC engine. There's no "Zetech" engine designation. Whether or not you need to replace the EGR valve is unrelated to which specific Zetec engine you have; both could require an EGR valve replacement if it fails. A malfunctioning EGR valve will cause a variety of issues, so that needs to be diagnosed separately.