check engine light came on 2 days ago... I have a code reader so I hooked it up and this is what I got: trouble code PO455 with possible issues being as follows
1. missing fuel cap - NO
2. incorrect fuel filler cap - NO/factory cap
3. faulty fuel cap - doesn't look to be anything wrong with it, fits tight and rubber gasket is in good condition
4. faulty fuel tank vacuum relief valve - not real sure but seems to be the greatest possibility, for this reason: when loosing the fuel filler cap I can hear the pressure built up in the tank releasing thru fuel fill spout
5. faulty or leaking EVAP canister - not sure, I have replaced a couple of the EVAP system components right after I bought the truck...
has anybody else experienced this type of issue?
any ideas or information is appreciated...
Luke in OKC

 

not much testing you can do without a scantool on the evap system, since the code is for a large leak you could check all the connections and hoses but its a lot easier to find an issue with a smoke test. May be a fuel tank pressure sensor issue also but in my experience its more common to be a leak.

 

i have a scan tool, is there a way to just scan the EVAP System?
do you have any info on the smoke test?
looking into the FT pressure sensor, thinking about just replacing it...
any opinion on the back pressure in the fuel tank? is it a hazard to continue to drive the vehicle?
thank you for all your help/info
Luke in OKC