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Based on those readings, either your cat is shot (how were the NOx levels?) or your car is running extremely rich. I saw a bunch of suggestions focusing on what would cause your car to run lean (and thus result in a lean mixture). I'd be more concerned with your off idle readings. The ECU should have been able to lean out the mixture enough based on the feedback it should be getting from the oxygen sensor. Of course you want to start with a basic tune up (plugs, cap, rotor, air filter, oil change) and make sure the car is at operating temperature when you smog it.
Anyhow. First things first. How much is the car warming up? You can/should use an infrared thermometer to check the temperature of the engine. If your car is really running cold, you should also be able to tell by the temp gauge not moving to its normal position (about 9 o'clock). If it's running cold, check for a dead or missing thermostat.
As a side note, I would concur that a so-called Italian Tune-Up is a great idea. 2nd gear on the highway. You should have a rev limiter (about 6000RPM) so basically go as fast as you can for a good five+ minutes. I'm able to keep up with traffic in 3rd gear on my wagon. Of course a tachometer wouldn't be a bad piece of insurance here either. Of course when performing the Italian Tuneup you should run some BG44K thru the fuel system. Better than Techron. As much as it pains me to say this, check with your local JiffyLube. Around here they used to (supposedly they're phasing it out in favor of some cheaper Pennzoil crap, because they make very little profit with the BG products) use BG44K as part of their fuel system service.
Next, you'd want to look at the fuel mileage. If it's really poor (I'd guess 15mpg or less.. you should be getting well into the 20s) your fuel pressure regulator may have failed (or the return line may be clogged). With the engine off pull the/a(?) vaccum hose from the FPR. I don't have a car with EFI so I'm not quite sure how this works. Regardless, there shouldn't be a significant presence of fuel. You could/should test the fuel pressure to verify it's really out of spec. In reality the FPR is a $40 part, and easier to replace than check or repair.
Might be worthwhile to check/replace the oxygen sensor. Check the voltage, etc. If it's the original one, it's almost certainly time for a new one. You should have a three (or four if someone splurged and went for a more solidly grounded one) wire sensor. No, you shouldn't put a one wire in there. Why? Because the three wire will help cut emissions when the engine is cold by reaching operating temperature (~600F) in a more reasonable amount of time.
If that's fine, or your mileage isn't so horrible the engine coolant temperature sensor may be out of wack making the computer think the engine is running really cold (this is not the same sender that powers the gauge). If the computer thinks the engine is cold it will dump lots of fuel in there. You can check the resistance across the sender's terminals at various temperatures to make sure it's in working order. The Bentley manual has the appropriate graphs.
If everything checks out it very well may be your catalytic converter has died. However a dead cat would (IIRC) show up as having high NOx, HC, and CO readings. A rich mixture tends to result in lower NOx readings, and a lean mixture tends to result in lower HC/CO readings.
- alex
'85 244 Turbo
'84 245 Turbo
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