Fuel injectors directly affect the air/fuel ratio for the engine and new fuel injectors do require a new or updated tune. We also suggest that you check the other component of the engine before installation. No special tools are required. It is easy to replace old fuel injectors. Each fuel injector has a protective cap that must be removed before use. For VW For Passat For GTI 2006 2007 2008 For EOS 2.0L I4 2007 2008 2009 Engine Parts 1/4Pcs Fuel Injector Nozzle 06F906036A Stable fuel injection pressure, reducing carbon deposits and poor fuel atomization caused by long term use of the nozzle; Improve efficiency fuel quantity delivery not only ensures full combustion of fuel, but also improves engine efficiency;, Manufacturer: ZXCTQQS