I have bad breath I can't smell. Brush floss nightly. No cavities or gum disease. Have tried nasal washes and saline spray. Any suggestions?

2 ideas. If you have ruled out dental or gingival disease as a cause of you halitosis, consider 1.) LPR or high acid reflux and 2.) chronic tonsillitis in which there are food particles caught in the crypts of the tonsils. The latter is a common cause of bad breath even in the absence of infection.
Breath smells. smells come from the sinuses, up from the stomach, or from the mouth. are you using a tongue scraper? from back to front 3 times after brushing your teeth. Could also be tonsaloliths, calcifications that hang on the tonsilar folds, can be nasty.
Lots. You need to brush AT LEAST 2x/day for 2 full minutes by the clock, or you're fooling yourself. Good that you floss daily. Gently brush top of your tongue also. Need to see Dentist (especially if it's longer than 6 months to check oral health). Need to see PCP to evaluate tonsils, sinuses, GI system, medications (fish oil for example can cause bad breath.