I'm driving a 2011 Prius with 94k miles on it. A few months ago I noticed that the mileage dropped from 42-45 to mid 30s and it has been like that since then. There has not been any change in the driving style, and I notice that the mpg is usually the highest when I am going 40-60 mph. I also noticed very slow acceleration and a strange sulfur like smell coming from the air vents when I tried to accelerate quickly. I tried different gas stations to see if it was the fuel and I used a fuel cleaner I found at AutoZone, but neither fixed it. I finally took it to the Toyota dealership and they said that it needed a "tune-up" which included them flushing the fuel and coolant system and replacing the spark plugs. However, after the tune-up the slow acceleration, poor mpg, and the weird smell continued. I used a diagnostic system tablet to check the hybrid battery, but there didn't seem to be any issue with that. The battery charge also looks normal on the dashboard. I've looked around this forum, but I see a lot of people with the same issue, and I have already tried a lot of the suggested solutions. Anyone know what could be the issue?
what is the history on the car? how many miles did you have it before the problem started? you might want to get dr prius app and run a health check on the battery. also worth checking the wheels for rubbing brakes. unfortunately, you got ripped off by a dealer who knows about as much as i do
I would do a BG hybrid repair kit which you can get on Amazon. It has an engine flush, oil additive, and fuel cleaner. I would also change atf fluid and both coolants. I know you mentioned the dealer already changed the coolants for you but did they do both inverter and radiator coolant? Or only one of them?
You're getting a hydrogen sulfide smell because your catalytic converter is failing. Eventually it will get very clogged and the car will have less power, may even be hard to start. Has this car been burning a lot of oil? that's usually how a cat clogs in the first place on these. That shop fleeced you, nothing they did was relevant to your car's condition. Never go back there.
Did you take it back to the dealership and tell them to give you your money back because what they told you was wrong did not fix the problem?
Before they did the tune-up I asked if it would actually fix the issue. They just said they couldn't guarantee anything, but that since the car was nearing 100k miles that a tune up was recommended anyway.
They scammed you. They are just "guessing". There really is not any such thing as a "tune up" anymore with electronic ignition and fuel injection. The plugs were due at 100,000 or 125,000 so that was the only thing semi legit. Look at the maintanence book for the schedule of service. You could also ask to see a print out of the scheduled TOYOTA items...
