How To Get Rid Of Odor In Vents. Spray an antiseptic into the exterior air vents (where your car pulls air from outside into the car from). Speed up the process of getting the odor out by running the air conditioning or heat when you’re not home.
Give it a few days and if you still have holding tank odor, then check. You will see lots of objects flying out. Try emptying your tank first and then throwing in some tank treatment with some fresh water.
What you need to do is get an odor removing spray, febreeze, lysol, one that will kill bacteria, and odors.
You might also want to get a diy vehicle odor remover and sanitizing kit. How to get rid of holding tank odor. This is where things get really messy. The air conditioning system takes air in from the outside through these vents, cools it, then blows it throught the vehicle.