EGT block off plate (1/8 NPT thread size) that fits ALH and BEW TDIs We also supply a fresh egr gasket and two copper pinch nuts. Will not fit A3/B4 TDIs. 
 

The exhaust gas temperature (EGT) can be one of the most important parameters on a turbo diesel-powered vehicle. It can warn the driver of situations that are potentially damaging to the engine, and it can also be used as a guide for optimizing fuel economy
 
Diesel engines are not indestructible. Aside from running a diesel without oil, or filling the fuel tank with gasoline instead of diesel fuel, few things will damage or kill a diesel engine faster than excessive exhaust gas temperature (EGT), yet strangely enough, TDI's are not equipped with a pyrometer as standard equipment to monitor EGT. During normal operation of such vehicles, EGTs usually stay within safe limits, but situations can occur where the EGT gets too high, doing serious engine damage without any warning to the driver. A pyrometer that displays a diesel’s EGT can warn the driver of dangerous conditions before such damage occurs.