Skip the auto shop - Our mechanics make house calls

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

asked by on

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.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: The car has an autocheck report of 90.

Hey there. Failing the emission test is less of a concern than failing a safety inspection. Emission testing failure could be as simple and innocuous as the car having a loose gas cap and setting a DTC. But...

Q: Won't start

You first need to check and see if the engine has lost fuel pressure or spark. If you lost fuel pressure then you need to locate the fuel inertia switch in trunk on the trunk hinge bracket. The switch will...

Q: Hello Richard my name is Jose and i was wondering why my 01 expedition accelerates when i turn it on or change gears but only once

The engine should be checked to see if the PCV hose at the connection on the intake is broken causing a large vacuum leak. If the line is leaking it will cause the engine to idle and run faster than...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Distributor O Ring Last?
The distributor is part of the ignition system in your vehicle and its purpose is to route high voltage from the ignition coil to the spark plug. The spark plug then...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.