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Q: If my codes for my engine light is P0305, P0430, P0442.

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If my codes for my engine light is P0305, P0430, P0442 If i get P0305 fixed will i be able to pass emission without getting the other codes fixed on the same day.

My car has 294000 miles.
My car has an automatic transmission.

To answer the question will I pass emissions if P0305 is fixed: if the two other codes are cleared after repairs are done for the P0305 code and they do not come back then you may pass emissions. The code P0305 is for a misfire on cylinder 5 and this misfire could cause the code P0430 for catalyst damage may happen from the engine running rich.

Fixing the misfire should fix this P0430 code. The last code P0442 is for a small evaporative fuel system leak and could be due to a loose or leaking gas cap, leaking connections on the fuel tank fill tube hose, or a leaking evaporative purge valve leaking.

You will need a smoke test done to see what is leaking on the vehicle. This is done using a specialized white smoke machine to fill the system with smoke and a leak will allow the smoke to leak out. If you only fix the misfire code and then clear the codes, then the engine will need to pass all the monitors again before it will pass emission testing in most states.

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