Gas cap is new, so I suspect that the 2 are related- I'm thinking when my engine was put back together, something cracked or is loose. Any ideas where I should look first? THANKS!

 

455 is a gross evap pressure leak, start checking all your lines and seals, if you cant find it you will probably need to do a smoke test.

 

Just got same code. Do I need to start checking all gas line hoses and seals or can it be internal engine seals etc..? I don't have gas smell and nothing leaking but horse power seems to be lacking at times. Thanks

 

If your gas cap is good, and most are then you must check every square inch of the evap syatem all the way to the tank and the best way is by doing a soake test.

 

Ok im all in but can you give me a starting point or a reference point from the RAVE manuel. Thanks again!!!

 

Mike- I notice the fuel smell when I put the key in the "2" position before starting her up...does this isolate a certain place to start for me? thanks pal

 

Possible small fuel leak at the rail/injectors when first priming, but that won't cause an evap code to pop up.

 

A physical Nitrogen flow test needs to be done, with non-DMTL trucks, you can throw a 455 code and not have a leak at all. If it fails a flow test, then smoke it. If it passes, you're looking at a restriction in the purge line, or something going on with the tank pressure sensor.
With the fuel smell at key on, get your eyes on that leak, liquid gas should not be leaking out at all, and can give you big problems if it gets any worse.
Also, make sure that not only the gas cap is good (usually is when it's new) but that it's fully seating on the filler neck, and not binding up and 'ratcheting tight' before it actually seals.

 

Check all the purge plumbing.
This is on the driver's side.
There is a vacuum bottle with a few vac hoses, the purge valve and hoses.
Make sure none of this is leaking.

Maybe replace the gas cap too.

Check the rubber fitting from gas cap to the gas tank.

Was the fuel pump out?
Maybe leak at that seal.
But, leaking fuel pump seal would stink all the time.