Truck will not pass smog test

Question

P0307 then a p0307 pending pops upChanged spark plugs checked coils and the injectors and wires all ok. Now having catalyst and evap showing on reader. Will not pass smog please help

Answer 1

P0307 Misfire cylinder number 7

One of the most damaging code are misfire code, the main purpose for the CK ENG LT is to protect the catalytic convertor and the catalytic protects the envioment. , Misfire are type "A" code condition which are catalyst damaging. The damage may just have occured, clear the code give it a good highway drive , hopefully the catalytic code will not set. As for the EVAP code the fuel cap should always be the first inspection if the cap is worn replace.