Our 1993 240 wagon has repeatedly given a check engine light over the past 3 months. We bring the car in to our mechanic, who has hooked it up for analysis and keeps telling us that the " report" is inconclusive. He mentions that several sensors are mentioned in the report, but none are said to be the main culprit. They turn off the check engine light, and, well, within a day or two, it's back. The car runs fine ! The car idles fine, starts fine etc. Having searched this forum, I do not think it's the AMM from reading several posts.
I brought the car to another shop and was told it may be the 02 sensor or another part of the "environmental" system. Any suggestions would be appreciated. Is it common for check engine reports to be inconclusive ? We love this car and just want to take care of what is needed.