Replace the failed EGR Coolers & Components in your 2020-2025 Chevy/GMC 6.6L L5P Duramax. The EGR cooler is designed to lower the temperature of exhaust gases that are recirculated back into the engine. A portion of exhaust flows from the exhaust through the EGR Cooler, where it is cooled before being circulated back into the engine. EGR coolers are a known weak point on many diesel engines and are prone to leaks or blockages. One of the initial signs of failure can be white smoke exiting the tailpipe. This is steam from boiling water or coolant. If the EGR cooler has cracked or failed, the coolant passages can begin to leak. The coolant will start to mix with the exhaust and will enter the intake. Next, it is heated by the exhaust or inside the combustion chamber and is then pushed out the tailpipe. Besides white smoke, you may also start noticing a reduction of coolant in your overflow bottle or degas tank. If you have to occasionally fill your coolant system, and you dont notice any drips or spots on the ground, the coolant may be exiting through the exhaust. Another item to check is the EGR valve. It will typically be covered in carbon buildup and be a dark black color. When coolant enters the EGR system, it can mix with this carbon. Small amounts of coolant can mix with this carbon and will create a sticky buildup. In some cases, there may be enough coolant passing through to strip away all of the carbon. This can result in the valve looking like it has been cleaned. Common symptoms that the EGR Cooler could be failing are smoke exiting the tailpipe, loss of coolant, sticky EGR valve, or possibly a check engine light (CEL). Since the EGR cooler connects the exhaust and cooling systems of your engine, failures inside the cooler can lead to a loss of coolant, overheating conditions, and possibly damage to the engine. Factory OE-style replacements and upgraded EGR cooler designs are offered for a variety of diesel engines. Shop all the top brands such as Bullet Proof Diesel, Bostech, Alliant Power, Grizzly Air, Dorman, PPE, AFE Power, XDP, and more!