Hi, my name is Devin. I am an auto repair expert with the Car Genius team here at RepairPal. So sorry to hear you're having trouble with your vehicle.
A strong ammonia smell during acceleration in your 4Runner could be related to the catalytic converter or the emissions system. Catalytic converters convert harmful gases, and sometimes, if they're malfunctioning or there's an excess of nitrogen oxide (NOx) buildup, you can get an ammonia-like smell. Since this issue has been present since you bought the vehicle, it might point to a defect with the emissions control components, like the catalytic converter or the exhaust system. Given that it's a new car, it's best to bring it to the dealer to address this under warranty. Depending on mileage, you may also be experiencing oils or chemicals burning off from the manufacturing process.
If you need more advice, have any other questions about your vehicle, or would like to get connected to a RepairPal Certified shop near you, we have you covered. Give us a call at 877-913-1554, and we will happily help you out!
