thanks for your respect trichard- followed your advice and looked up the faq. while it applies to 740s and 940s, much of it may be applicable to 240s; not sure about whether the 740 and 240 obd 1 is the same. while studying the faqs, i found a blurb about swedishbricks which looked good but the webpage for it was dead. always trying to have an alternative plan when surrounded by congs with only a half a clip left, i went to a dig out and study of bentley . the obd 1 page xp gave the procedure to use the obd and a code list . curiously the list gives a 2-1-2 code for oxygen sensor signal missing or faulty . i am suspecting this is the problem, but i may be surprised. regards oldduke