An EGR delete kit is an aftermarket part assembly that removes a vehicle’s EGR system. If you’re a diesel truck owner and want to improve engine longevity and overall performance, you may want to invest in or consider an EGR delete kit. The kit allows your truck’s diesel engine to run cleaner, last longer, and improve performance. I blocked off my EGR and added HLC (Hywy Lean Cruise) where I go to around 16.7 AFR and 42* advanced based on MPH and TPS feedback. In data logging I get zero KCs and they say you'll gain 10% MPGs. As for the argument the EGR reduces NOx, it does. So does a 3-way Cat, which I have. Finally, oil; catch cans and AOS (Air Oil Separators) are for completely different reason than EGR,EGT, or TGV.. These are to remove the PCV system, or if you have a built engine that has cold oil blow by. The PCV is Positive Crankcase Ventilation, this system collects the oil vapor that in the old days was just vented to the open air, into An EGR delete gets rid of the EGR system. Some aftermarket performance kit lets you remove the EGR valve to prevent exhaust gas from being routed back into the engine. The benefits of deleting the EGR system include a boost in horsepower, better fuel economy, longer engine life, and reduced engine temperature, among others. For example, the first and most common problem with the MBE 4000 engine is the leak from the head gasket. Well, replacing the gasket along with rethreading the cylinder surface help in the long. And don’t forget to pull out the injector and valves, suggested by some DIY automotive experts. Then, the lack in torque can be reachable up to 1100 So I replaced the oil cooler and deleted the EGr cooler on my 07 6.0. Changed the injector o-rings, dummy plug, stand pipe, copper washers and one reman injector all on passenger side bank.Went to start it and it fired up after maybe 7 long cranks but was smoking white like crazy and misfiring. Figured it was air in the system and let it run Some people choose to fit an EGR delete and a catch can. This is less common as its the most expensive option and in most cases unnecessary. Oil going through your motor without the carbon is much less of a problem. Yes, you’ll end up with pipework covered in oil and the intercooler will be less efficient, but its much less of an issue. Once its in the combustion chamber it goes out the tail pipe. This is my very limited explanation on what the system does. Oh yeah and an EGR delete isn't legal everywhere because something to do with causing prius drivers cancer or some shit. 2005 GMC 2500HD 6.6 LLY. 6" lift. 35" all terrains. Straight 6" exhaust (no cat or muffler). JK02hU.