Who knows how to interpret an auto zone read out?

I went to auto zone and had my car scanned. They gave me four problems that I have listed below. Obviously I have more than one problem. But which one is more important? And which one should I replace first?





P0306 - a misfire has occurred in cylinder #6.





Definition:


Cylinder misfire detected - cylinder #6.


Explanation:


The power train control module monitors the crankshaft speed and had detected a misfire


condition.


Probable causes:


1. Ignition system fault


spark plug(s).


ignition switch.


wire set.


ignition coil.


2. Vacuum leak.


3. Injector fault.


4. High or low fuel pressure.





P0401 - there is insufficient flow in the exhaust gas recirculation system.





Definition:


EGR system fault (exhaust gas recirculation).


Explanation:


The ECM has detected too little flow on the EGR system.


Probable causes:


1. Blocked passage on EGR system.


2. Failed EGR valve.


3. EGR solenoid faulty.


4. Failed EGR pressure sensor.





P0443 - a malfunction exists in the electrical circuit for the purge control valve in the evaporative emission control system.





Definition:


EVAP (Evaporative Emission System) purge/vent solenoid circuit condition.


Explanation:


The solenoids and system wiring are monitored for opens or shorts.


Probable causes:


1. Purge or vent solenoids defective.


2. Check connector and wiring.


3. Fuel saturated vapor canister.


4. Failed EVAP vent solenoid.





P0500 - a malfunction exists in the electrical circuit for the vehicle speed sensor.





Definition:


Vehicle speed sensor malfunction.


Probable Causes:


1. Open or short circuit condition.


2. Poor electrical connection.


3. Failed VSS.|||You didnt state wht kind of vehicle you are working on. These codes are very common on ford cars.#1 replace the spark plug wires. #2 check the hoses between the egr tube and the dpfe senso one or both are probably broken.#3 check vacuum lines and wiring for the evap system.#4 replace speed sensor.|||Does the vehicle regularly miss? I would start there, replacing plugs and wires. If that doesn't do it, you may have a bad injector.





Next thing would be to replace the egr, or take it off and clean it with seafoam|||Misfire for sure. As it says you should probably at least check your #6 spark plug wire %26amp; spark plug, if that doesn't work check your #6 injector.





VSS is probably the least important since last I checked the VSS does nothing but make your dash and cruise control work and if you can live without them it's better to focus on things relative to your engine.||| I would not let Auto Zone scan my car, they are wrong way to many times. They do not even get close.