Customer called us out for a slow draining toilet in the master bathroom. I tested the fixtures in the bathroom and the toilet appeared to be the only one affected. The left bathroom sink was also slow draining. I recommended clearing the toilet with a closet auger, clearing the p trap and pop up in the sink and endure to maintain pipes and septic. Customer agreed. I poured a cap of endure down the kitchen sink. The removed the p trap and pop up from the left master bathroom sink. Cleaned them both and tested the sink. It was running very well and had no leaks. The I used a closet auger on the toilet but I was unable to relieve the blockage. I attempted to use a plunger after and noticed the style of toilet was allowing air through the bowl and into the tank. The toilet has its own venting system that often gets clogged or damaged and makes the toilet unable to flush. I recommended the customer replace the toilet due to the cost of repair and the likelihood of repeat issues. I left the