EGR System Cleaning

Whenever the Exhaust Gas Recirculation (EGR) valve is removed the EGR system should be inspected and cleaned if necessary. This will ensure that the EGR system will function properly under all operating conditions. Proper EGR system service consists of the following.

1. EGR System Diagnosis:
   
   Diagnosis of the EGR system should be performed if Powertrain Control Module (PCM) Diagnostic Trouble Codes (DTC) are set. See appropriate SELF-DIAGNOSTICS article.
2. EGR Valve Pipe Cleaning & Checking For Leaks
   
   Turn OFF the ignition. Clean and check the EGR pipe from the exhaust manifold to the EGR valve. See EGR VALVE PIPE .
3. EGR Valve Cleaning
   
   If the EGR system is operating correctly, the EGR valve can be removed, checked for deposits, cleaned, and re-installed. Use the following procedure for this operation.
   • Remove the EGR valve from the engine. See EGR VALVE .
   • While holding the EGR valve base in your hand, try to rotate the connector housing. Replace the valve if it exhibits looseness.
   • Inspect the EGR valve pintle and seat for deposits. Use a cloth or other suitable soft device to remove deposits. Remove all loose particles. If the deposits are such that pintle/base interface cannot be cleaned adequately to allow the pintle to seal against the seat, replace the valve. Damage to the powdered metal EGR valve base will occur if cleaned with solvents, sharp tools, a wire brush or wheel, or by sand blasting. Cleaning by these methods is not recommended.
   • Install EGR valve on the engine using a new gasket.