P0449 and p0455
 

My CEL cam on in my 2008 ls panel... the codes are 449 and 455... i have changed the vent solenoid and the gas cap with no luck... any idea where i should go from here or what i could so to figure this out??

EVAP Vent valve under the rear of the car

https://www.obd-codes.com/p0449

As you said gas cap, or other leak in EVAP system, check fuel vapour line up above the rear axle and try to blow through the purge valve under the hood, it should be closed and not allow air in either direction

https://www.obd-codes.com/p0455

Did you check the fuse? Under hood #64

you my friend are a legend!! how did i not see that fuse... its blow... however im waiting for a purge solenoid so im gunna replace that anyway... if that fuse fixes this i owe you a coffee or something!!

It would be a good idea to find out why it blew.

well all last summer the light would come and go... so im thinking the vent valve was packing its bags then..

so after changing fuse and the purge the light went out for about 2 mins and the light came back on for p0449

The wires have been known to fray.

So did the fuse blow again?

Did both codes arrive at the same time or did you ignore a CEL for awhile?

If the fuse blew again it could be a short (duh.) If it didn’t you could try clearing the codes, or did you already do that?

I don’t see how you have an explanation for P0455 yet tho.

The good news is a large leak might be easily found with a smoke test. I have a nagging P0442 small leak, too small for a smoke test to detect, apparently.

P0449 Evaporative Emission (EVAP) Vent Solenoid Control Circuit
P0455 Evaporative Emission (EVAP) System Large Leak