was wonderin is there any suggestion from people this is what i did to the car after i fail the smog test from the ref cuz i got a ticket from the cop.
i replaced.. the 02 sensor the cat (used)
did a tune up ( dizzy cap, rotor,spark plugs, wires, and pcv valve), changed the oil, changed the air filter. and it has and bolt on exhaust. i did a pre test and it passed at 15mph and it pass at 25 mph expect for the nox. any suggestion. i have to go to the ref again next week. thanks