Some possibilities are the egr valve, is faulty, the oxygen sensor is faulty. The catalytic converter may be clogged. This can also mean you need to service your emission system which means if nothing is wrong to simply reset the light here is how.
2001-2005 Tribute, 1997-2004 B-Series - MIL ON
WITH DTCS P0442 P0455 P0456 P0457 P1442 OR CHECK
FUEL CAP LIGHT ON WITH DTC P0457
Some vehicles may exhibit a MIL (Malfunction Indicator Light) with DTC P0442, P0455, P0456, P0457 or P1442 or a Check Fuel Cap light illuminated with DTC P0457. These conditions may be caused by loose or leaking fuel cap or leaks anywhere in the evaporative emission system between the fuel tank and the engine.
Testing procedures described in this bulletin use the Mazda Evaporative Emission Tester P/N 134-01049. When using another tester follow the operating instructions for your tester.
Evaporative leaks may be caused by a loose, dirty or faulty fuel filler cap. Do not clean or replace the fuel filler cap until positively identifying it as the source of a leak through testing.
Check out the diagrams (Below). Please let us know what happens.
Sunday, March 14th, 2010 AT 9:05 PM