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Emissions Failed in 1996 993 C2

Old 05-31-2009, 12:46 AM
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Join Date: May 2009
Posts: 1
Default Emissions Failed in 1996 993 C2

1996 Porsche 993 C2. 21k miles. Failed Emissions.

Car has no CEL on.
I checked the OBD Fault codes and System readiness. Cleared the fault codes and they have not returned after 140 miles of driving all day.
Motronic 5.2 M07
Current Fault Codes

Supply voltage

Secondary air injection system
Cylinder (1-3)
OBD status

OBD status - no warm up cycle pass
OBD status - warm up cycle fail
OBD status - driving cycle pass
OBD status - trip completed fail
OBD status - system fault fail
Emissions failed due to the OBD status failures I think.

The car runs fine. Any idea what to do in this case?
Old 05-31-2009, 02:34 PM
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Join Date: Apr 2005
Location: Overland Park, KS
Posts: 3,532

The secondary air injection code is probably what is causing it to fail. The 993's are notorious for that system and the ports in the heads to get clogged with carbon. There is an 6 hour repair where the system is flushed and attempts to run the carbon out. If that doesn't work, then the top end needs to be removed and have the carbon drilled out of the heads.
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