55 MPG --> 48 MPG --> 55 MPG (2007 Prius)

My 2007 Prius is now 68 K miles.

Between 0 to 62 K miles it get an average of 55 MPG two months ago it drop to 48 MPG. I did not know why until 10 days ago the engine light lid. I brought my car to dealer and the error code was P2401. Dealer replaced the Vacuum Pump Modulator Assembly (above gas tank, gas tank has to remove in order to replace the pump). After replaced the Pump above, I got back to 55-57 MPG right away.

So I guess the pump was bad when I got 48MPG, but the engine light was not lit because it was still within the limit.

Question:

1-How is the warranty of this Vacuum Pump Modulator Assembly (3 years 36K or 15 years 150K miles [FONT=&quot]([/FONT] [FONT=&quot]Partial Zero Emission Vehicle PZEV))?


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