Any tips? chasing a large exhaust leak po455

[BlueCollarTahoe]

been having this code for a long time, P0455, heres the run down

- all the emissions pieces were replaced with ACDELCO. from the gas cap to the piece in the engine bay, the name escapes me.

- ran smoke through the system both with less than half a tank of gas and a full tank of gas, no leaks visable anywhere both times.

- mechanic thinks its the gas cap trying different ones.

- when you run the AC in the heat you can smell gasoline fumes.

- no leask visable anywhere, pieces all been replaced, not really sure where to look next. i want this issue fixed before it gets hot, anybody got any experience with this? tips where to look next?

 

[new2yukon]

I had gas smell when I filled it and it sat in garage overnight. Found the line connection on the (evap canister?)near the (transfer case output?) had not been completely reconnected. In my case I suspect it was disconnected when a shop replaced the output seal and didnt get it fully snapped on. Havent smelled it since I found that last summer.

Try this link for more reading:

https://www.samarins.com/diagnose/p0455.html

 

[Doubeleive]

if you did a smoke test and had no leaks then one of the parts that was replaced is defective
there is a vapor canister & vent valve solenoid in back under the spare tire area, then there is a smaller purge solenoid up front on the intake.
I would be more suspect of the rear canister/vent valve with a large leak code

 

[BlueCollarTahoe]

i replaced all three parts 2 years ago with ACDELCO parts. i see there are a two different purge solenoids i may have gotten the wrong one. I dont mind the stupid engine light its the smell of the gasoline with the AC on. I want the interior of the truck to be comfy as possible this summer.i guess im gonna have to reorder all the parts acording to the VIN number and have them replace it all again see what happens.

 

[BlueCollarTahoe]

update: bought all three emissions pieces by the Vin code...mechanics pulls out the old vapor canister calls me over. the thing weighed three times as much..was bloated and you could hear the charcoal inside rolling around. been about a week..had the AC and the heat running..no code..no smell so far. mechanic thinks the peice was defective even though i biought it brand new AC DELCO two years ago. now that i looked back in the records...the purge solenoid was actually from autozone as i couldnt get the ACDELCO piece fast enough. may have had something to do with it. either way so far so good..replaced with all acdelco parts.