I am new to TDR and I do have a little knoledge to your question. Any thing that will make it easier fro your turbo make boost normally will help keep EGTs low. On the other hand, like a couple of the other members stated that the aftermarket filters may void your warranty if used. Reguardless of what the aftermarket filter manufacturers labels say, the oil and cloth filters do not filter as well as the factory filters. The owner of "Turbo Engineering Group", in Golden, Colorado told me that he can thank these after market filters for about 25% of his business. A typical diesel turbo spins, I was told, spins over 150,000 at full boost. Any little particle that hits an intake compressor at this RPM will cause a minute amount of damage. Over the course of the engine life this dammage adds up and eventually unbalances the turbo: turbo engineering group balances a turbo at around 100,000 RPM. The air entering a turbo at full boost is traveling just under the speed of sound so that little partle exerts a lot of force. I am no expert, but the man I learned this from is. He told me the first thing I need toi do is get that K&N out of my 02.