Your little Geo Tracker has undergone a lot of driving trials at your hands through harsh weather conditions and rough terrain - so check your Geo exhaust system to see how it has fared. Because of the vulnerable position of the exhaust system - on the underbelly of the car - the components can be damaged by rain and salt, as well as hard knocks on the road. A visual inspection will often show signs of rust, corrosion, dents and cracks in the exhaust system components. If you see signs of damage, it's time to replace your Geo exhaust system. A visual inspection is often enough to find damage to the pipes, hangers, clamps and brackets of your Geo exhaust parts. Heat shields are also prone to damage from hard knocks, so replace any that are missing or barely hanging on. If a shield is dented, unbolt it, and check the exhaust system for damage. In general, the Geo exhaust system is made up of parts such as manifold, header, air pump, converter, muffler valve and exhaust tip and pipe gasket. Each one might suffer from corrosion, dings and rust. Sometimes, the only indication of cracks or holes is a rough idle or noisy engine. A car with a worn-out Geo exhaust system might emit more pollution or suffer from weaker horsepower, as well as burn fuel inefficiently. All those are signs that it's time for you to do an annual inspection of your Geo exhaust system, then replace damaged parts.