16804/P0420/001056 - Catalyst System; Bank 1: Efficiency Below Threshold
Possible Causes
Leakage in Intake and/or Exhaust System
Catalyst faulty
Oxygen Sensor(s) faulty
Oxygen Sensor(s) Control faulty
Possible Solutions
Check Intake and Exhaust System for Leaks
Check Catalyst
Check Oxygen Sensor(s)
Check Oxygen Sensor(s) Control
Perform Oxygen Sensor(s) Aging Check
Special Notes
For 1.8T's experiencing this fault code, this thread may be useful:
http://forums.vwvortex.com/zerothread?id=663057 17608/P1200/004608 - Boost Pressure Control Valve (N249): Mechanical Malfunction
Possible Symptoms
Malfunction Indicator Light (MIL) ON
Power Loss
Possible Causes
Boost Pressure Control Valve (N249) faulty
Diverter Valve faulty
Possible Solutions
Check / Replace Boost Pressure Control Valve (N249)
Check / Replace Diverter Valve
Retrieved from "
http://wiki.ross-tech.com/wiki/index.php/17608/P1200/004608"
Category: Fault Codes
17705/P1297/004759 - Pressure Drop between Turbo and Throttle Valve (check D.V.!)
Possible Symptoms
Malfunction Indicator Light (MIL) ON
Power Loss
Possible Causes
Leaking Hoses and/or Pipes between Components
Boost Pressure Control Valve (N249) faulty
Diverter Valve faulty
Throttle Body dirty
Possible Solutions
Check Hoses and Pipes between Components
Check / Replace Boost Pressure Control Valve (N249)
Check / Replace Diverter Valve
Check / Clean Throttle Body
Perform Throttle Body Alignment
Special Notes
Did anyone install an extra (wrong) dump valve?
When found in the NAR 2.0T (BPY) check RVUTB: 01-09-03 or 2018919 for updated Crankcase Breather Valve
If the breather valve is faulty, full engine vacuum is typically found when removing the oil cap at idle.