Have you noticed a pungent, rotten egg smell coming from your car? Assuming you didn’t forget about a carton of eggs in your trunk, we’ll explain some common reasons why your car smells like rotten eggs below.
A Leaking Battery
The smell of rotten eggs is one of the most recognizable signs that your car battery is dying. When a battery gets old or damaged, it may leak battery acid, which is the source of the rotten smell.
Battery acid has a distinct, sulfuric odor, making the entire car smell like rotten eggs. If you open your car’s engine compartment and catch a whiff of pungent rotten eggs, check the battery for any signs of corroded terminals or leaks. If you find a leak, your only option is to replace the battery.
A Broken Catalytic Converter
Another common reason why your car smells like rotten eggs is an issue with the catalytic converter. The catalytic converter is part of your vehicle’s emissions system and filters out the harmful toxins and byproducts in the exhaust gases from your car.
But if the catalytic converter has an issue or gets broken, it can lead to a buildup of byproducts in the converter, which also causes it to overheat. The intense heat and byproduct buildup can cause the entire car to smell like rotten eggs. If you’ve also noticed that your car’s fuel economy has declined recently, it’s almost certainly a catalytic converter issue.
A Damaged Fuel Pressure Sensor or Fuel Filter
The issue with your vehicle may not be the catalytic converter itself but the fuel pressure sensor or fuel filter. The fuel pressure sensor regulates the fuel flow into the engine, and if it’s broken or off, it may allow too much oil to reach the catalytic converter.
With excessive oil, the catalytic converter will clog up and, as we discussed, create a rotten sulfuric smell. The fuel filter is similar, regulating fuel going to the engine; if it’s too worn and not doing its job adequately, it’ll leak to a clogged and overheated catalytic converter. Whatever the reason for the smell, if you get a whiff of rotten eggs from your car, you should have it checked out by a professional mechanic as soon as possible.