2000 Volkswagen Beetle high Nox emission failure

2000 VOLKSWAGEN BEETLE
50,000 MILES • 4 CYL • 2WD • AUTOMATIC
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THETODD
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Emission test showed Nox of 1028, limit is 485
CO% is 0.
HC is 7.
Mass airflow sensor and coolant temperature sensor replaced by dealer two days earlier. MIL light no longer lit.
Informed this vehicle has no EGR on a 2 litre gas engine.
Is the converter at fault with CO and HC so low?
If not, what else should be looked at?
Sep 14, 2010 at 3:41 PM
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RASMATAZ
  • ✓ASE Certified Mechanic
  • 75,992 POSTS
  • ASE Certified Mechanic
Could be the catalytic converter or a computerized control system stuck in the open loop mode
Sep 14, 2010 at 4:03 PM
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THETODD
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[quote:121c506be7="rasmataz"]Could be the catalytic converter or a computerized control system stuck in the open loop mode[/quote:121c506be7]

Converter was found to be holed. Had to be small as little difference in noise was detected. However, was the culprit for sure. High Nox now very low Nox.
Thanks for the quick reply.
Sep 17, 2010 at 11:11 PM
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