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P0440 Diagnostic for 1999 Pontiac Montana After Fuel Pump Replacement

Model: 1999 Pontiac Montana Fault Code: P0440 Posted: 2016-05-15 13:34

I own a 1999 Pontiac Montana and recently replaced the fuel pump with a brand-new original equipment (OE) unit. Following this repair, my vehicle began displaying fault code P0440, indicating an issue with the Evaporative Emission Control System. The fuel pump is now functioning properly—so where should I focus my troubleshooting efforts to resolve this EVAP-related error?

Related fault codes

P0440

Comments (2)

Anonymous 2016-05-15 14:01

P0440 is a general EVAP system fault indicating the vehicle cannot maintain proper vacuum in the evaporative system. Since you recently replaced the fuel pump, it's likely that the repair introduced an EVAP leak or a malfunction in the Fuel Tank Pressure (FTP) sensor. This type of code is relatively common after new fuel pump installations and should be investigated carefully.

Anonymous 2016-09-28 00:15

P044-than codes originate from the evaporative emission system and may stem from an old or faulty gas cap, a defective fuel tank vent valve, or a malfunctioning EVAP solenoid. These components are common sources of leaks that trigger P0440 in 1999 Pontiac Montanas.