I was checking out another problem (pulsating lights - solved in a sister post) and I checked out the diagnostic codes while I was at it. The car (1990 745 16 valve) runs fine. But the old 2-3-2 code comes up for the fuel injection system - running too lean or too rich at idle. I suspect too lean because the car gave high NOx in a recent emmissions test which is consistent with a lean condition, not a rich one. Running rich would give high CO and mine was quite low.

There were no other codes. I can generate a slight ping if I tromp the gas when the revs are low coming off a stop. It'a a stick shift.

Vacuum hoses seem good but I will do the spray test again. Some of them may have been replaced by PO and the general under-hood condition is near pristine for a car with 335,000 km. I cleaned the throttle body in-situ last year. Maybe it is time to take it off and do a proper job.

It is a minor problem but I would like to cure it since it might cause trouble down the road if there is someting up that might be stressing the AMM or something. And I would like to get the NOx reading down. Suggestions? Time for new injectors?

Thanks in advance,
Bill
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Volvo Info Site 1990 745GLE 16valve