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I would appreciate some input on the following issue as I understand it is common with the 993 series:


The engine light is on; the dealer diagnosed the problem, and find out CO build up: "Problem is in air flow to air injection ports in exhaust ports. Suggest to treat passages chemically in attempt to clear airflow. If not possible, cylinder heads will have to be removed and sent to a machine shop to clear. At this point, it is recommended that the valve guides be replaced and valves checked."  Also, I was told this issue will happen again after about 20K miles or so...


Well, this is about a $1,800 fix option that may work as per the dealer...The car will not pass smog at this point.

Anyone experienced this issue with their Porsches? Any recommended solution?



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This is common on the n/a 993. Not as common for the 993 Turbo, but it does happen. You should post this same question over on Rennlist. Many experienced owners over there.


Side note, a great oil for your car is Mobil V-Twin 20W50.

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Btw, thank you White987S for the Rennlist posting suggestion; lots of help regarding my problem from that Forum too! :thumbup:

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