P0457/p0451 air box?? Purge valve??

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Asked by Visitor on June 13, 2024 Just got code after doing spark plugs, wires, and valve cover gasket. Sparks are seated and gapped properly, wires are making good contact. Pcv hose has no holes to gasket. I noticed the air box I removed to get access to the valve cover gasket was not clipped into place properly. Could this trip the 0457 code? Or is it more likely to be the fuel injectors or purge valve. TIA

What makes this problem better or worse?

Driving a short while

How long has your 2005 Subaru Forester had this problem?

3 days