2002 Golf TDI. List of fault codes:: P0671-674 Cyl. 1 thru 4 glow plug circuit P0402 EGR FLOW EXCESSIVE DETECTED P0128 COOLANT THERMOSTAT BELOW REGULATING TEMP (is that really a bad thing??) P1556 No DTC definition found. I've reviewed the VTN post. I will start there to address the limp mode issue. Question is this: Are any or all of the other faults related? P0671 thru 674 I believe may be a harness issue (as I was told from the dealer). Old Blue has 150,000 + miles and still averaging 43 mpg ~ 2.32 gal/100 miles. Any information is greatly appreciated.