Can my chronic sinusitis cause ear infection/pain?

I have a deviated septum and see the ENT next week.

I'm not sure about it being the CAUSE of an actual infection, but you can definitely have them simultaneously and just having sinus problems can definitely cause ear pain and pressure. I went to the doctor thinking that I had an ear infection, and it turned out to actually be a sinus infection. What was happening in my case, was that my nose was not running, so all that stuff was actually collecting behind my ears (Gross, I know) and causing a lot pf pressure and pain. The doctor gave me Flonase and that loosened everything up. I started getting a runny nose after that for a while, but it really relieved the pain in my ears.If the inflammation in your nose is severe enough to block the eustachian tube at the back of your nasal cavity, you could develop ear infection. The eustachian tube connects your middle ear to your nose for drainage and pressure equalization.
Chronic sinusitis is very often due to allergies... particularly mold, and mycotoxins (the harmful byproducts of mold). Sinusitis definitely causes ear pain, congestion... and possibly infection. Try Debrox, an over the counter doctor approved drop that really helps.

Most antibiotics are fungal based, therefore, they can make a fungal infection like "Fungal Sinusitis" much worse, so stay away from those, if you can. If you take antibiotics and you can worse, it's a sign that the problem is possibly fungal, and you are feeding it with the drugs.

Your doctor will try to talk you into sinus surgery... (ENT doctors make their fortunes on sinus surgery...) Beware! Sinus surgery is one of the MOST painful surgeries, and often does not help! The recovery time is weeks, if not months, and often results in addiction to pain medications.

Try EVERYTHING else first... SINUS RINSES, ETC., Most important, figure out the triggers and what you are allergic to, and then eliminate the allergens from your home or work environment. It could be dust mites, pollen, mold...check for signs of water damage (paint pealing, drywall bubbling/crumbling, mold stains around plumbing fixtures, toilet overflowing...)... in your home and work... leaking/clogged pipes can cause hidden mold to grow in your walls, crawlspaces, ceilings, etc.... mold is a VERY common cause of Sinusitis.
Experience.