The exhaust system in your diesel engine is responsible for removing the burned exhaust-air mixture from the combustion chamber. It is then diverted to the tailpipe before being released into the atmosphere. But the mixture will contain hazardous toxins unless it has been treated properly. Diesel engines use aftermarket emissions reduction systems to limit the amount of nitrogen oxide gas leaking into the air, including selective catalytic reduction (SCR) and exhaust gas recirculation (EGR). Diesels must have these parts in place to comply with the latest environmental regulations. 

The SCT system involves spraying a diesel exhaust fluid into the exhaust gas mixture, which reduces the amount of NOx coming out of the tailpipe by converting it into gases that form naturally in the atmosphere. The EGR system involves diverting a portion of the used exhaust gas away from the tailpipe, so it can be recirculated through the combustion chamber. This reduces the amount of heat needed to burn the air-fuel mixture, which limits NOx emissions.

Both of these systems need regular maintenance. We sell a wide range of exhaust system replacement parts and components at Bostech Auto, including EGR coolers, sensors and SCR parts that keep your engine from overheating. Each part relies on sensors to perfect the emissions reduction process. If the system fails to properly treat the exhaust gas, it can spread debris throughout the engine, causing crucial parts to clog and fail. Coolant can leak into the crankcase and gaskets and seals will break if the system gets too hot. Be sure to replace your exhaust system when you notice problems under the hood.