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Dave Nova
Dave Nova, Chevrolet Technician
Category: Chevy
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Experience:  ASE Master Certification. GM World Class Certification
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Chevrolet Impala can you tell me what car codes P0128, P0404,

Resolved Question:

can you tell me what car codes P0128, P0404, and P0440 for a 2001 chevy impala means?
Submitted: 6 years ago.
Category: Chevy
Expert:  Dave Nova replied 6 years ago.
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The code P0128 sets when the engine coolant does not reach proper operating temperature. Make sure the coolant level is full. If it is, then replace the thermostat.

The code P0404 sets when there is a fault with the egr valve. This typically requires replacement of the egr valve.

The code P0440 sets when there is a leak in the evaporative emissions system. Most of the time this is due to a loose gas cap or a bad seal on the gas cap.
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