EVAP Gross leak

The ODB says large leak so i don't think its my gas cap also CEL doesnt come on after getting gas so I think the gas cap is ok...... any suggestions or somthing. thanks alot

My inspection was due a week ago

 

Having same issues with P0450, P0454 & P0455 intermittently.
Keep reseting with scan gauge but come back randomly. I suspect a cracked vacuum line
that goes away when warms up but haven't found it yet.

 

If the gas cap seal is good then the system needs to be inspected.

 

k i know this is a old post but i inspected all my lines and whatnot...
I replaced my purge valve and the CEL automatically went away

 

Glad you found it.

 

Where is the purge valve located?

 

On the cooling fan under the hood drivers side(USA car)

 

After finding same code you guys had po455 and reading this topic i decided to change purge valve too. It didnt help, code is still there. Today i took the tank down to inspect charchoal canister and hoses, everything seems to be fine. What else to inspect, i cant pass inspection with cel constantly coming back for this one code.

 

You need to somehow add pressure to the system and check for leaks.

 

you mean like a smoke test? i thought of that too, i will do it if nothing else helps. i didnt think that gas cap could actualy trigger GROSS vacuum leak, now i am reading here that is possible too?!

 

Yes that is very possible.

Yes like a smoke test. I made a special tool to add pressure to the system. Then spray with soapy water and look for bubbles.

 

ok, gas cap is cheap, i will try that next. What kind of tool, if its something easy to make-please share so i dont have to pay for smoke test.

 

This easy enough?
https://volvoforums.com/forum/volvo-s70-33/home-made-special-tool-18125/
I also use a vacuum/pressure guage with that.

 

pretty neat

 

Thanks!!