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Old 08-30-2007, 04:22 PM
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richtazz richtazz is offline
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Re: 1997 Chevy Lumina 3.1 L - Surging Problem

Checking the EGR feed tube for carbon buildup is very good suggestion. If it appears clear of carbon, a bad vacuum line to the map sensor will cause what you describe as well. The PCM reads the change in vacuum at the MAP sensor when it commands the EGR to open to test it's efficiency. A cracked vacuum line will cause a P0401 code to pop up, even when the EGR is perfectly fine.
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