[Sshaw928]

My 1992 968 failed emissions. HC(PPM) Limit 100 Mine at 360, Co % Limit 0.53 Mine 11.45, NOx limit 1167 mine 57 all at 2835 RPM.



I have a check engine code 1223 which as I understand is "oxygen regulation"

I have put in a new Bosch oxygen sensor and a DME temp sensor. Plugs were replace less than 2K miles ago. engine has about 20K since complete rebuild. ANy help on what to do next would be greatly appreciated.





Stephen <img src="/forum/images/smilies/968/sad.gif" class="smilie" alt="" />

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[flash]

that is very odd



we need to know what non-stock components are in the car (chip, cat, etc)

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[S_Cal968]

Did you happen to notice what color the spark-plug electrodes were when they were replaced? Black/dry is fuel fouling [rich condition] and black/wet is oil fouling - tan color is normal.

Also have you kept up with the fuel system service? The high readings may be 1 or more injectors that are leaking, [also could cause a rich condition].

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[4matic]

Mine wouldn't pass. It needed a new Cat. With new Cat it was perfect. Almost emission free. If you're close a mechanic should be able to get you through smog.

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[Sshaw928]

[quote name='flash' post='49600' date='Mar 22 2008, 10:27 AM']that is very odd



we need to know what non-stock components are in the car (chip, cat, etc)[/quote]



All Stock , no add ons.

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[Sshaw928]

The 968 is completely stock. No add-ons. The plugs were Black and saturated with gas when I replaced them. It Starts hard when cold. That is , it starts but runs very rich to the point I have to rev it to 2500 to 3000 RPM for 20 to 30 seconds to clear it before I can put it in gear and drive away. I have in te past had to pull the fuel fuse , turn it over clear the fuel and then put the fuse back in to get it to start. It seens to be putting way to much fuel in at start up . Again only when cold in the morning . the rest of the time it starts fine. That said , I replaced the DME II temp sensor. (it had set a code indicating the sensor was bad). Things got better but it still seems rich at start up.

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[S_Cal968]

That could very well be a leaky injector(s). There are several vendors that specialize in injector service & reconditioning which check for leakage. volume and spray pattern. If the injectors have never been out of the car it may be well worth it to have this service done. While you're in there, perhaps check the fuel pressure.



Just for regular maintenance I run concentrated injector cleaner once or twice annually as well as clean the MAF when the air filter is serviced. I use Lubro Moly Fuel System Cleaner or something similar. And, CRC spray cleaner for the MAF.

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