Will a faulty EGR valve cause the engine not to start?

A faulty EGR (Exhaust Gas Recirculation) valve is unlikely to directly prevent an engine from starting. While a severely stuck-open EGR valve *might* contribute to a no-start situation under very specific circumstances (e.g., by drastically altering the air/fuel mixture), it's not a primary cause. A no-start condition is usually due to problems with the fuel system, ignition system, or the starter motor itself.

A faulty EGR valve is more likely to cause problems *after* the engine has started, such as:

* Rough idling: The engine might run rough, especially at idle.

* Poor performance: Lack of power and hesitation during acceleration.

* Check engine light: The car's onboard diagnostic system will likely illuminate the check engine light and store a diagnostic trouble code (DTC) related to the EGR system.

* Increased emissions: More pollutants are released into the exhaust.

If your car won't start, it's best to focus your troubleshooting on the more common causes of no-start conditions before investigating the EGR valve.