My deck is still tackey after sealing and staining. What should I do?

Did you let the stain dry before sealing?  How long as the stain/sealing been on?

Or even, was the decking dry before you stained it?
Or was the stain and/or sealer adequately mixed?
Or was it too cold, or damp out, or late in the day toward evening
when you applied the sealer?
Or are you sure that the stain and sealer products work together and
for this application?
Did you do the work yourself or have a knowledgeable tradesperson do the work?

Best of luck

The deck was dry. It was a stain sealer combo by Behr #501. It was 70
outside and I started in the morning. I did it my self only applied
one coat with a sprayer and back brushed. Sealer/stain was mixed well.

It definately sounds like you know what you're doing.  I know how
frustrating it is to work a project carefully and still have somethng
screwy happen to it.  I wonder if the product was chemically damaged
in the warehouse (froze or got too hot)?
Have you tried the tech. support at their website?   www.behr.com 
Let us know if the tackyness goes or if there is a trick to resolving
soemthing like this that we can all learn from.
regards - synapse666b

Well, after two weeks, it appears to have finally dried. So, the
leason here, when the stain says one to two days. they mean one to two
weeks.

I'm betting that your deck was pine.  
The oils/resins in pine easily keep paints/stains/sealers from
'drying.'  Actually, they act as a solvent and slow the drying of
finishes tremendously.