My CEL came on today, does anyone know what these two codes are? It's missing very badly.

P 4055 and P0304

 

p0304 is cylinder 4 misfire

 

p0455 is evap leak

 

What is evaporator leak?

 

its part of your emissions control system look for vac leaks check hoses and manifold for leaks

 

Thanks man, I'll check those lines. If I've got a leak that could explain the missfire on #4, right?

 

pretty much check plugs and wires while your at it and it wouldnt hurt to clean the maf

 

a misfire usually means either plugs, wires, or coil pack

 

at 74k miles its a good idea to change plugs and wires anyway!! give it a good tune up

 

Don'tSay, the evap code is probably from the hose
that was disconnected at the spare tire location in
your other thread. It appears to be an evap cannister
purge valve, and will trip a code if it's not working
correctly. These evap valves start sticking as the miles pile up.

That's probably not causing the miss, however.
As was stated, maybe check the plug and wire on the
number 4 cylinder (driver's side front).

 

Thanks alot man, I'm having plugs and wires installed tomorrow.

Let you know then!

 

check your fuel cap, i got that a couple of times, just tighten it a little more,. amd it should fix that

 

Got my new wires and plugs today. What a difference! It's running great now! Must have needed them for awhile.

Thanks to all that helped out.

This is a great site!