I'm new to this site so bear with me. My first problem is that on my 98 Mercury Sable my check engine light recently came on. I ran my ODB II reader and it said it had that the speed sensor was malfunctioning. I was reading some other posts about speed sensors and a lot of the time it was something other than the sensor itself so I am beginning to doubt. The car also starts having symptoms other than what I would expect with a faulty sensor. When I go over about 60, the speedometer goes to zero. Shortly after that, the overdrive on/off light starts blinking. Around that time, my power steering also goes. And when I drive at slow speeds, it feels as if it were about to stall, as if it was a manual transmission. A couple times, if I drive around a lot, it acts as if the transmission is starting to go. If anyone has any ideas on that, please let me know. I'm a newbie at this kind of stuff.
Problem #2:
Last year, when I had to change the engine on my 97 Ford Taurus, I picked up an engine at a salvage yard. After putting it in, I found out that they had sold me a blown engine. So I brought it back and they readily gave me another one. I put that engine in, and everything works fine, the only problem now is that the check engine light doesn't turn off, and hence, it can't pass inspection. I ran the ODB test and it just says the code for engine compartment (or something along those lines). I brought it to a shop and they said they couldn't find a thing wrong with it at all. I'm wondering if the salvage yard possibly gave me, say, a '96 engine that my '97 computer doesn't fully recognize and therefore shows an error for it. I was wondering if there is any way to tell what year an engine is (whether it is the correct one or not) or if there is any other ideas that might be the cause of the problem. Thanks.