Single Diaphragm Valve

• 1). Locate the EGR valve in your vehicle. It is usually found on the intake manifold.
  
  
• 2). Disconnect the tube connected to the EGR valve's nipple.
  
  
• 3). Connect the tube of the hand-held vacuum pump to the nipple of the EGR valve.
  
  
• 4). Pump the hand held vacuum pump to around 5 or 6 inches-Hg. The pump should retain the same pressure. If it doesn't, the valve needs to be replaced.
  
  
• 5). Start the vehicle. While the vehicle idles, start pumping up the hand-held vacuum pump. If the EGR valve is good, the engine should stall as you pump the vacuum.
  
  

Positive Back Pressure Valve

• 1). Locate the EGR valve in your vehicle. It is usually found on the intake manifold.
  
  
• 2). Disconnect the tube from the EGR valve's nipple.
  
  
• 3). Connect the hand-held vacuum tube to the EGR valve's nipple.
  
  
• 4). Start the vehicle. Depress the accelerator until the engine reaches 2,000 rpms.
  
  
• 5). Pump the hand-held vacuum pump and watch the rpms. The vehicle's rpms should drop about 100 rpms with each pump if the EGR valve is working properly.
  
  

Negative Back Pressure Valve

• 1). Locate the EGR valve in your vehicle. It is usually found on the intake manifold.
  
  
• 2). Disconnect the tube from the EGR valve's nipple.
  
  
• 3). Connect the hand-held vacuum pump to the EGR valve's nipple.
  
  
• 4). Apply 5 to 6 inches-Hg by pumping the vacuum pump. The pump should retain the same vacuum if the EGR is working properly.