I cooked some Turkey sausage out of the casing in about 3/4 a tablespoon of canola oil (recipe called for olive oil). I tried to drain out most of the grease. I added some soft cheese to it and served in a pizza roll. When I bit into it, something tasted a little off. I can't describe it, but I didn't care for it. Was it the oil or the fat I was tasting? I'm hesitant to just lick the canola oil to determine if that was it.
Oils and other fats can go rancid if old and not properly stored. Cooking oil should be kept in a cool, dry place with minimal exposure to air. In my experience, Canola oil goes rancid faster than many other oils.
One quick way to see -- smell your oil from the bottle. You could also try heating a small amount in a pan, dipping bread in it, and tasting it. It's best to isolate your components when searching for off flavors.