Audi EGR valve replacement

Repaired this one at the customers house, customer requested EGR valve change. This part is quite common point of failure on all vehicle brands. EGR is an acronym for exhaust gas recirculation and the EGR valve is an emission control technique. it works by reintroducing exhaust gases into the combustion chamber which cools cylinder temperatures as a result this stops oxides of nitrogen forming creating cleaner tail pipe emissions, one of the negative sides to this is this process contaminates the inlet system with carbon deposits.