I'm sure you can find the answers by using the search on this board. Before you do it though, you may want to make sure you won't get into trouble while doing a smog test. The EGR is something the inspector will check if you have to do smog testing in your state. Also it's there for a good reason, to reduce NOx and other emissions. As long as you don't mind the occasional cleaning, there really is no other reason to do this mod. Using a clean-burning additive like StarTron and doing the occasion Italian tune-up will keep the intake fairly clean so you shouldn't have to do this cleaning very often even if you decide not to do the mod.

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2004 VW Jetta TDI (manual)

Past MB's: '96 E300D, '83 240D, '82 300D, '87 300D, '87 420SEL