What to do if I smoked 16 days ago can I pass a urine test tomorrow?

Cannabis on UDS. I believe you are asking that if you smoked cannabis could it still be in your system 16 days later. Chronic users of cannabis can be positive for urine long after their last use since thc remains in fat cells. In some cases months after the last use. Infrequent users generally no longer will have a positive test after 2-3 weeks. However, these are only rules of thumb and there are exceptions.