On the 2004 Kia Spectra, the P1401 is pointing to a problem in the EVAP (emissions control/recovery) System. If the fuel cap has already been replaced, and you are sure the replacement cap meets Kia specs (those “universal” or “locking” fuel caps sold at after market parts stores do not meet OE specs, and will not seal the system correctly) then next thing to look at is the Fuel Filler Neck. Make sure there are no cracks or holes and that it is sealed tightly to the fuel tank. If the visual inspections check ok, then a very common fail item associated with this code is a faulty Purge Solenoid Valve. You can find the Purge Solenoid is located under the hood. Mounted towards the rear of the engine compartment, just about at the center. Inspect the vacuum lines going to each end of the Solenoid for any cracks, holes or loose/missing connections. If the visual inspection checks ok, replace the EVAP Purge Solenoid.
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