After you vape weed (dry herb), is there any THC that remains on the spent bud?

I have an effecient vape pen which does great for oil and wax. I have tried to vape bud, but it doesnt give me the desired effect. It not reaching the temp to properly detox the herb is my reasoning. So..i think your leftovers will have a fair amount of thc left behind.

Try to oil, you never know your luck.