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Emissions fail - obd scanner

  • 17-09-2021 3:55pm
    Registered Users Posts: 3 cianbrannigan1

    my car recently failed on emissions 

    its a golf mk5 1.4 petrol 2006

    i attached images of what my obd scanner is reading as im not too sure what they mean


  • Registered Users Posts: 74,319 ✭✭✭✭ Atlantic Dawn

    Hard to know exactly, can you show what the fail figures were from the NCT printout so we can see how far out they are? Had the car being lying up idle for some time recently?

  • Registered Users Posts: 3 cianbrannigan1

    Yes the car had actually been lying up for a few months

  • Posts: 0 [Deleted User]

    Check the fuses.

  • Registered Users Posts: 4,865 ✭✭✭ SCOOP 64

    You must have good OBD scanner that does emissions test , i would check for leaks in exhaust any split leaking air pipes in engine bay , take it you took it for a good run before test.

    Post edited by SCOOP 64 on

  • Posts: 0 [Deleted User]

    O2 sensor heater circuit can triggers the most of these faults on that list Catalyst, Oxygen sensor and Oxygen sensor heater. 2006 year O2 sensors was designed about 160-200k. If these kilometers is on the clock, just replace both sensors. Even if these working, the heater circuit may bit lazy and it can trigger the fault.

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  • Registered Users Posts: 3,052 ✭✭✭ John.G

    I wouldn't think its a exhaust leak as the lambda reading is spot on at 1.0, if an exhaust air leak present, ironically, the emissions, especially the HC readings can decrease because they are being diluted.

    I always change the plugs immediately before the NCT and clean the throttle body especially if that engine has exhaust gas recirculation (EGR) as the oil being drawn in can carbonize, causing the throttle plate to stick, the ECU then advances the ignition timing which can lead to a higher CO reading, (and the engine to pink) the high HC reading is generally due to engine wear, piston rings worn etc, but not a problem for you just yet.

    If you are handy yourself, can advise on throttle body cleaning without removal.