My check engine light came on so I checked the edge diagnostic feature and it gave:
PO455
Evaporative Emission system leak detection
Gross leak / no flow
Where do I start?
Thanks

 

Make sure your gas cap is tight!

 

If it tight, replace it for s&gs. There is a seal in the gas cap that can fail and throw that code. My wifes envoy threw it and i went straight for the cap which was broken. Replaced cap and cleared the code. No more cel..

 

ahhh, thanks guys
I will tighten it now and see if it throws it again

 

I made sure the cap was tight and no code yet

 

Might not have been the cap, but it's a cheap fix if the code doesn't come back.

I had a code one morning after a rough start, sort of like it was starved for fuel. Check engine light and code on the Edge Evo. Evap leak. Cleared the code and it didn't come back, but next gas fill-up, the cap was loose. Good luck!