Dash light on, code 400 or EGR

2002 MAZDA B2300
200,000 MILES • 2.3L • 4 CYL • 2WD
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BOB NEALE
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  • 2 POSTS
Can this be cleaned on vehicle or must transmission be removed? Also, is there a vacuum relay before EGR? Thanks, Bob
Jan 26, 2019 at 5:56 PM
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SCGRANTURISMO
  • ✓ASE Certified Mechanic
  • 4,897 POSTS
  • ASE Certified Mechanic
Hi Bob, my name is Alex and I will be helping you today. Yes, your EGR can be cleaned. Use brake/card cleaner and get where the EGR pipe connects to the EGR valve and the EGR valve connects to the throttle body. There is a EGR vacuum regulator that when commanded by the PCM/ECU opens and allows vacuum to reach the EGR valve, opening it and allowing exhaust gas to enter your throttle body and be reburned in the engines combustion process. Here is a helpful link and a few images for you: https://www.2carpros.com/articles/how-emission-control-systems-work
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Jan 26, 2019 at 11:27 PM
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