engine warning light on...For the techs out there....help

[H3CAN]

OK,

My enfine warninng light SES came on.
I checked the regular...gas cap tight, fuel octane ok etc....but the light was still on.

Took it to the dealer, they ran smoke test for leak and also got P0455 on scan (evap system). They checked and checked and could not duplicate....which is no surprise to me ...!

Anyone seen that ? any ideas ?

Also, since I was there, I pointed out that my engine bottom block is slightly oily on the driver's side....the dealer could not find the leak and washed the bottom (and charged me $60 bucks )


Any one have seen those symptoms at 7500 miles...I hope I will not regret buying a GM. I love this truck.

Thanks