hey all

i had just gotin some gas and about 10 maybe 15 miles before my service engine light had just come on, now i just replaced my EGR valve and got to damn thing to turn off...anyways. i went to autozone and had em do the check up, and it says my catylist eficiency(i cant spell rofl) below bank(1) or some crap like that the code is P0402

now does that mean my cats are busted, bad gas or my o2 sensors are shot?

 

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