Filters have been clogged with wet cat litter and now the vac will turn on but shuts off and wont cont to vaccume. can we clean/rinse the filter out. filter light has come on and then turns off once the vac shuts down.. thanks

If the loss of suction occurred during wet vac,the float has blocked the discharge vent , and this can be cleared by unplugging vac and emptying tank. if you tip the unit over while running it will close exhaust vent and can be cleared by turning unit off and wait 1 minute and restart unit.The most common causes of loss of suction are dirty filters or a clog in the hose. To troubleshoot, remove the hose from the vacuum, place your hand at the opening of the tank inlet and turn the vac on.
If you feel suction at the inlet, the issue is with your hose or accessories. Check your hose and accessories for a clog. If no clogs are found, check the hose for a hole or crack - even a small crack can cause a loss of suction. If a crack or hole is found, replace the hose.
If you do not feel suction at the inlet, turn the vacuum off and unplug from the outlet. Follow the steps in the user manual that came with the vac to clean the filter. Check the filter for rips or tears; replace with a new filter if any are found. Empty the tank or if you are using a collection bag replace it if it's full. Make sure the filters are properly installed then secure the housing to the tank. Plug the cord into the outlet, turn the unit on and place your hand at the tank inlet to check for suction. If you still do not feel suction at the inlet, turn the vacuum off and unplug from the outlet. Check the tank for any cracks and make sure the drain cap, if applicable, is secured to the tank.

With no suction you should check the venturis. They can become clogged if you suck up wet dust, wet cat litter, etc. You\'ll need a Torx Screwdriver to get it apart. See where that gets you.

There is a thermal reset in the motor that will shut the motor off if it gets too hot from a clog or clogged filters. It will come back on when it cools down. If it does this try to find a clog somewhere and also replace or clean your filters

the vac filters are blocked it will shut off the power untill you clean the filters or replace

Have you replaced the post motor filter? It could be time to do that.
Perhaps your cyclones are clogged as well. You can find steps to disassemble and clean your cyclone, pretty easy actually. Only 6 parts inside there and they only go together one way so you can't screw it up. Search google for dc14 cyclone disassembly and you'll probably find the video. I just did my DC17 and it took about an hour total to take apart, clean and then reassemble. You can also take the opportunity to wash all the parts and disinfect with a mild water bleach solution. That'll help with the smell.
I am betting though that your post motor and premotor filters are the blame for the smell.
I bought my DC 17 from some lady who used it to clean her cat's litter boxes. Cyclones were totally clogged after only 6 months. What do you expect from poop and wet kitty litter. She said it was junk and bought a $1500 Kirby in it's place. She's gonna have some new and interesting smells with that machine sucking up wet kitty litter.

Where did you buy this unit from? Go back there and ask if they have filters for yours. Otherwise look in the Yellow Pages for vacume cleaner repair shops. Sometimes they have all kinds of filters for all kinds of vacumes. You can try places like Wal Mart. What you want to look for are filters that will work with your unit. The foam filter you refer to is called a pre-filter. It traps the bigger particles so they won't damage your paper filter or clog it up especially if it's wet stuff you're picking up. You can remove that foam filter and gently wash it out in the sink with a mild dishwashing liquid and warm water. And even sometimes if you have time you can wash a paper filter out by hosing it out from the inside, with just a gently rinsing on the outside. Don't use any solvents on it just soap and water. And don't use high pressure either, as it will destroy the paper. I have cleaned my paper filters several times before I finally had to replace them. You can also look at places like Lowe's. They carry shop vacs and a whole assortment of attachments as well.

its probably clogged up with cat litter.might have gotten into the motor.your motor has a motor guard inside if it. when it overheats it will shut down till it cools off.you need to clean all th cat liter out of it.and clean the filters.with a direct drive you might want to take it in to a repairman to sevice. its not a shop vac i advise you not to pick up things like cat liter

You will have to clean the filter and clean the main motor.  I had this issue on mine and the main motor was so full of dust bunnies, that it stopped it from creating a vacuum.

Check that the filters are completely clear and not blocked - especially the top filter on top of the bin assembly. If its clogged completely brush it free of dirt and then reassemble. Make sure the inner cone filter and mesh filter is also completely clean. Then check the hose and main dust channel - something is clogged that makes this machine overheat and stop working - and often with this model (Hoover also make it in the UK under the Alyx name) its down to clogged filters or small clogs of dust in the dust channels. 
Don't forget to rate, thanks.

First thing is to check all your hoses, and filters. Filters rob your vacuum of air flow which equals power.. I don't think that you have a clog so much as I am inclined to think that you have dirty filters. In a wet vac, you can rinse your filters out, but they will eventually need replaced. It's a good idea to have an extra filter around for such an instance.