I have an 01 fabia that recently failed its mot on engine warning light. Load of codes including coolant temp and lambda sensor. Replaced everything with new and still get two codes coming up 17549 and 17526, both seem to be lambda related again, the sensor was brand new from a reasonable source. Is there anything else that could cause this? or am i looking at replacing the lambda sensor again? already checked for vacuum leaks etc.

Thanks in advance

Paul

The thing with DTC fault codes is that it doesn't directly mean that the sensor itself is at fault! The wiring may have failed somewhere so it's a case of checking for a chafed wire or shorts etc in the looms. Check for continuity to the ecu and check resistances etc.

Autodata is good for data and pin outs for wiring.

Edited 2 July, 201214 yr by Dj4man

Probable causes for code 17549, load calculation - implausable value, are:

• wiring
  
• intake leak
  
• MAP (manifold abolute pressure) sensor
  
• MAF (mass air flow) sensor
  
• TP (throttle position) sensor
  
• APP (accelerator pedal position) sensor
  
• throttle control unit
  

Probable causes for code 17526, heated oxygen sensor - heater open circuit, are:

• wiring open circuit
  
• HOS sensor
  

Hope this helps.

SN