Well, it has been almost a year since the nightmare started. I replaced the front O2 sensor on my 855 turbo. I ordered from A1volvoparts.com and they sent me a universal one. After much red tape and angry phone calls they finally admitted their mistake and sent a Bosch sensor with a the right plug. The light has been on ever since. I finally gave up and was ready to let the dealer change the sensor again so it had a warranty. Before I took it in I checked with the parts dept. for the Bosch number. The number didn't match-the second one A1 sent was for a non-turbo! Gee, that's great- now it's too late to send it back & I threw another $800 at a problem that didn't exist. Well at least I have spare computer, all new vaccuum hoses, intake gasket, etc., etc. I also have a slightly used spare O2 sensor for a non-turbo if anyone needs one. I ordered the correct one from eeuroparts.com and it arrived the next day (free shipping too!). The light has been out for 3 weeks now.

Thanks to everyone on brickboard.com who offered their expertise on my problem.

I guess the lesson for today is- Never assume that anyone, anywhere, at any given time knows what they are doing. Double check everything!

(PS-Sorry for the long post!) Doug