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Failed State Emissions with High Co%


Model: 993, Year:1995, Mileage:74,500, Type of use:Both Street & Track
Hi,My 993 failed NJ inspection with a high CO% reading of 1.32 (state limit is 1.20).I cleaned the MAF sensor, replaced the air filter, and tightened up the 20 or so clamps in the air-intake system. It then failed with a reading of 1.77 so it got worse. Next I replaced all 12 spark plugs, ignition wires, and both pairs of caps and rotors. Also I put a bottle of Techron in the tank. The next inspection test showed an improvement to 1.26 (a mere .06 over the limit). My Porsche dealer then did a short-test with their scan tool but that showed everything was w/in spec.The O2 sensor was replaced in 2004 at 58K miles. What would you recommend next? TIA, Tom

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