Q: How do you know if your secondary air injection system is bad?

Hi David, Generally when the secondary air pump goes bad, this will cause the motor to run rough due to the incorrect readings being generated by the oxygen sensors as well as overall lack of horsepower. This is all caused by the imbalance created by the air injection pump not inducing additional air onto the exhaust. By this not happening, this causes the oxygen sensors to read incorrect exhaust gases which then get translated to the computer as the engine needing more or less fuel. When this happens, this can cause the motor to be over or under fueled depending on the air needed in order to run properly. Ultimately, this will also cause the car to fail an emissions test as well depending on the requirements of your state. Should you need additional help in determining if your pump is bad, I would recommend having one of our certified mechanics come to your location to inspect your car.